Smartwatches / Compare

Fitbit Sense 2 vs Xiaomi Watch S5 46mm

A

Product A: Fitbit

Sense 2

105 of 150 known

Change Fitbit Sense 2

Compare the Xiaomi Watch S5 46mm with

Search smartwatches

B

Product B: Xiaomi

Watch S5 46mm

89 of 150 known

Change Xiaomi Watch S5 46mm

Compare the Fitbit Sense 2 with

Search smartwatches

All 150 fields

Every value links to where we found it.

Only differences

AFitbit Sense 2

BXiaomi Watch S5 46mm

General

7 of 10 differ

Series

Sense4Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 23 October 2026Fitbit names the product Sense 2 in its Sense line and calls it its most advanced health-focused smartwatch.

Watch S3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Overview Q3 compares the Watch S5 46mm with the Watch S4 in the same Watch S line.

Model numbersiMaker identifiers for this exact model and its listed variants. Excludes sibling models and other generations.

FB521, FB521BKGB-US, FB521SRWT-US, FB521GLBM-US1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Regulatory notices name Model FB521 with FCC ID XRAFB521. The retail colour model numbers come from the Abt listings.19Retailer pageabt.com/Fitbit-Sense-2-Graphite-Aluminum-Shadow-Grey-Strap-Advanced-Health-Fitness-Smartwatch-24mm-FB521BKGBUS/p/182315.htmlRead 23 October 2026Abt lists manufacturer model FB521BKGB-US. FB521SRWT-US and FB521GLBM-US are on the sister Abt listings. FB521 is the model in the manual.

M2530W1, BHR08IVGL, BHR08ISGL, BHR08ITGL, BHR08IXGL4Maker spec sheet (PDF)i02.appmifile.com/257_operatorx_operatorx_xm/29/08/2026/b4c07745b195e649523c370b72bc9ae7.pdfRead 20 October 2026EU Declaration of Conformity for radio equipment model M2530W1, Smart Watch, dated 29 August 2026. The declaration page names it Xiaomi Watch S5 46mm.11Retailer pageammancart.com/products/smartwatch-xiaomi-s5-46mm-silver-bhr08isglRead 20 October 2026Silver: part number BHR08ISGL. Two retailer part numbers in the job brief point to the black version, but retailers list BHR08ISGL as Silver and BHR08IVGL as Black.12Retailer pagemsystems.gr/smart-watches/xiaomi-watch-s5-46mm-black-bhr08ivglRead 20 October 2026Black: part number BHR08IVGL.13Retailer pageofficespot.gr/shop/all-categories/wearables/smartwatches/xiaomi-watch-s5-46mm-blue-bhr08itglRead 20 October 2026Ceramic Blue: part number BHR08ITGL.14Retailer pagebatna24.com/de/p/smartwatches-und-sportarmbander/xiaomi-watch-s5-46mm-jungle-green-bhr08ixgl-70278-m2530w1Read 20 October 2026Jungle Green: part number BHR08IXGL from the product code in the page address. The page ties it to model M2530W1. Other retailers list BHR08IXGL for Jungle Green.

GTIN / EAN

810073611429, 810073611443, 81007361143619Retailer pageabt.com/Fitbit-Sense-2-Graphite-Aluminum-Shadow-Grey-Strap-Advanced-Health-Fitness-Smartwatch-24mm-FB521BKGBUS/p/182315.htmlRead 23 October 2026Abt lists FB521BKGB-US with UPC 810073611429 (Graphite Aluminum with Shadow Grey band).

6932554463397, 6932554463366, 6932554463373, 693255446341011Retailer pageammancart.com/products/smartwatch-xiaomi-s5-46mm-silver-bhr08isglRead 20 October 2026Silver EAN 6932554463366.12Retailer pagemsystems.gr/smart-watches/xiaomi-watch-s5-46mm-black-bhr08ivglRead 20 October 2026Black EAN 6932554463397.13Retailer pageofficespot.gr/shop/all-categories/wearables/smartwatches/xiaomi-watch-s5-46mm-blue-bhr08itglRead 20 October 2026Ceramic Blue EAN 6932554463373.14Retailer pagebatna24.com/de/p/smartwatches-und-sportarmbander/xiaomi-watch-s5-46mm-jungle-green-bhr08ixgl-70278-m2530w1Read 20 October 2026Jungle Green EAN 6932554463410.

AnnouncediThe maker's first announcement of this model. This is separate from first retail availability.

24 August 20224Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 23 October 2026Blog post dated Aug 24, 2022. Pre-orders started that day with worldwide availability that fall.

28 May 20269Press articlefonearena.com/blog/483795/xiaomi-watch-s5-price-features.htmlRead 20 October 2026Article dated 28 May 2026 with the same euro and pound prices as Gizmochina. The USD figures in the article are conversions and are not stored.

Status

Available2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026The Google Store sells Sense 2 at 249.95 USD on the access date. That is a current price, not the launch price.

Available2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026The global product page is live with specs. Trade press says it is available now from 28 May 2026.

PredecessoriThe model this one directly replaced, in the same line, tier and size, as the maker or a trusted review names it.

Not available

Xiaomi Watch S416Reviewgsmarena.com/xiaomi_unveils_smart_band_10_pro_buds_6_sound_play_speaker-news-73032.phpRead 23 October 2026GSMArena says the Xiaomi Watch S5 comes as the successor to the Watch S4.

SuccessoriThe model that directly replaced this one, in the same line, tier and size. A revision such as a Slim or OLED model does not count when a next generation exists.

Not available

Not available

Launch price (US)iThe maker's US launch MSRP for the stated configuration, excluding tax. Current store prices and later discounts do not qualify.

$299.954Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 23 October 2026Versa 4 is available for $229.95 and Sense 2 is available for $299.95 (USD). US prices exclude sales tax.

Not available

Launch price (EU)iThe maker's euro launch price for the stated configuration, including VAT as published. Current store prices and later discounts do not qualify.

€299.9514Spec databasenextpit.de/smartwatches/google-fitbit-sense-2Read 23 October 2026UVP 299,95 EUR, marketed from September 2022.15Press articlepcwelt.de/article/1206707/fitbit-sense-2-vorgestellt-hier-finden-sie-alle-infos.htmlRead 23 October 2026PC-Welt (Germany) at the launch: Die Fitbit Sense 2 kostet 299,95 Euro. German prices include VAT. Tech Advisor states EUR 299.95, GBP 269.99 and USD 299.95.

€179.998Press articlegizmochina.com/2026/05/28/xiaomi-watch-s5-46mm-globally-launched-specs-priceRead 20 October 2026Launch report of 28 May 2026: Black and Silver 179.99 EUR and 149.99 GBP, Jungle Green and Ceramic Blue 199.99 EUR and 169.99 GBP. Euro price with VAT as published. The Xiaomi pages show no price and the country behind the euro price is not named.

MarketsiISO country or region codes where this exact model or variant is sold. A source page's language does not establish availability.

US, GB, DE, AU2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026US, GB, DE and AU Google Stores offer the model with a Buy button. Current prices are not launch prices.

EU, GB8Press articlegizmochina.com/2026/05/28/xiaomi-watch-s5-46mm-globally-launched-specs-priceRead 20 October 2026Prices are given in euros and pounds. Xiaomi has no official US release.

ColoursiThe maker's own colour names

Shadow Grey / Graphite Aluminum, Lunar White / Platinum Aluminum, Blue Mist / Soft Gold Aluminum2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Colors: Shadow Grey / Graphite Aluminum, Lunar White / Platinum Aluminum, Blue Mist / Soft Gold Aluminum.

Black, Silver, Ceramic Blue, Jungle Green1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Four colours: Black, Silver, Ceramic Blue and Jungle Green.

Segment

Smartwatch2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Page title: Fitbit Sense 2 Smartwatch. The Aug 24, 2022 Fitbit blog calls it a health-focused smartwatch.

Smartwatch3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Overview Q2: product positioning is a Xiaomi series long battery life smartwatch.

OS updates promisediYears of explicitly promised OS updates. A security-only support period does not establish an OS-upgrade promise.

Not available

Not available

Security updates untiliExact end date published for security-update support of this model. Do not calculate it from a stated number of years. A security-only period does not promise OS upgrades.

Not available

May 20285Maker spec sheet (PDF)i02.appmifile.com/127_operatorx_operatorx_xm/17/07/2026/fbc4923c53bffffff7fc441114771351.pdfRead 20 October 2026UK PSTI statement for M2530W1: the defined support period is until 05/2028. Read as May 2028. This is a security-support period, not an OS-upgrade promise.

Case

6 of 8 differ

Case sizeiMarketed case-size options. The marketed size can differ from physical case height, such as ceramic editions. Base dimensions describe the smallest base-material case.

Not available

46mm1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 202646 mm body. The separate 41 mm Watch S5 has its own product and is not included.

Case shape

Rectangular14Spec databasenextpit.de/smartwatches/google-fitbit-sense-2Read 23 October 2026Gehäuseform: eckig (square).

Round3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Screen: 1.48-inch AMOLED circular screen.

Case materialiMaterial of the housing body, not just the bezel. Use Mixed when the maker describes a mixture of housing/frame materials. Read the published-material field for the parts and proportions.

Aluminium1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Materials: the housing and buckle on Sense 2 are made of aluminum.14Spec databasenextpit.de/smartwatches/google-fitbit-sense-2Read 23 October 2026Gehäusematerial: Aluminium.

Stainless steel1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Frame row: watch body stainless steel. The bezel is stainless steel, ceramic or forged carbon by version.

Case material (as published)

Aluminum1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Materials: the housing is aluminum. The store names the finishes Graphite, Platinum and Soft Gold Aluminum.

316L stainless steel frame with stainless steel bezel3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Body Q3: the middle frame is stainless steel and the bezel is stainless steel, ceramic or forged carbon. The overview page says the watch is crafted from 316L stainless steel.

BackiMaterial of the back of the smallest base-material case. Other materials or regional editions can differ. See source notes.

Not available

Not available

Case dimensionsiPhysical case height, width and thickness. The source note states exclusions such as the heart-rate sensor protrusion.

Height40.5Width40.5Thickness11.2mm(1.6 × 1.6 × 0.4 in)2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Dimensions and weight: length 40.5 mm, width 40.5 mm, height 11.2 mm. The page states no sensor exclusion. The same page states weight 37.64 g without saying whether the band is included, so no weight is stored.

Height46Width46Thickness10.99mm(1.8 × 1.8 × 0.4 in)1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Dimensions 46.00 x 46.00 x 10.99 mm. The maker excludes the strap and protrusions. The FAQ gives 13.14 mm with the heart rate sensor protrusion.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Body Q1: diameter 46 mm excluding DECO, thickness 10.99 mm excluding the heart rate sensor protrusion. 13.14 mm including it.

Weight (case only)iWatch body without a strap. An unqualified published weight must not be assumed to exclude the strap.

Not available

45.6g(1.6 oz)3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Body Q1: Black 45.6 g, Silver 45.3 g, Ceramic Blue 45.7 g and forged carbon Jungle Green 43.5 g. The specs page says about 46 g without the in-box strap. The FAQ does not say whether the strap is included, so the specs page wording is taken to apply.

Weight with strapiWatch with the stated strap attached. Strap material and case size belong in the source note. Reviewer measurements belong in measured fields.

Not available

Not available

Durability

2 of 8 differ

Water resistanceiStatic water-pressure rating in atmospheres. It is not a safe swimming or diving depth. Diving limits are listed separately.

5ATM2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Water resistance: water resistant to 50 m. The Google compare page states 5 ATM.9Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 23 October 2026Maker comparison, Water and dust resistance row: Sense 2 5 ATM.

5ATM1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 20265ATM, equivalent to 50 m. The maker says it is not suitable for hot showers, saunas or diving.

Water resistance standard

IEC 605291Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026IP Rating, printed page 78: Model FB521 has a water resistance rating of IPX8 under IEC 60529, up to a depth of 50 meters. IEC 60529 covers ingress, so no ISO pressure standard is inferred.

Not available

Dust and water rating

IP6X, IPX81Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026IP Rating: IPX8 under IEC 60529 up to 50 m, and IP6X dust-tight. Stored as the two published codes.

Not available

Dive rating

Not available

Not available

Max dive depthiMaker-rated depth for the stated diving use, not a conversion from the water-resistance pressure rating.

Not available

Not available

MIL-STD-810iMaker claim that the watch was tested against specified MIL-STD-810 methods. It is not a guarantee for every military-standard test.

Not available

Not available

MIL-STD-810 tests

Not available

Not available

Operating temperatureiPublished operating range. Source notes identify on-wrist limits and other operating conditions. Storage or charging limits are excluded.

Min-10Max45°C1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Environmental conditions, printed page 63: operating temperature 14 to 113 F (-10 to 45 C). Non-operating and charging ranges (0 to 35 C) are not stored.

Min-10Max45°C3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Charging and Battery Q1: operates from -10 to 45 C and charges from 1 to 45 C.

Display

7 of 14 differ

Display type

OLED2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Display: AMOLED display.

OLED1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 20261.48-inch AMOLED display. No LTPO is stated.

Display type (as published)

AMOLED2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Display: AMOLED display.

AMOLED1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Screen sizeiPublished active display diagonal for a rectangular display, or diameter for a round display. Do not calculate it from pixels or display area.

1.58in(4 cm)12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Display size 1.58 inch. Notebookcheck and nextpit state the same. Fitbit publishes no diagonal.14Spec databasenextpit.de/smartwatches/google-fitbit-sense-2Read 23 October 2026Displaygröße: 1,58 Zoll.

1.48in(3.8 cm)1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Resolution

336 × 336px12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Display resolution 336 x 336 pixels. Notebookcheck states the same.

480 × 480px1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Pixel densityiPublished pixel density. A rectangular diagonal formula must not be applied to a round display.

Not available

323ppi1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Display area

Not available

Not available

Touchscreen

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Navigate Sense 2: color AMOLED touchscreen display and 1 button.

Yes3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Screen Q2 and Q3: swipe control and wet-touch protection. Underwater operation is not supported.

Max refresh rateiHighest published display refresh rate in active operation.

60Hz18Measurementnotebookcheck.net/Fitbit-Sense-2-Smartwatch-review-Automatic-activity-recording.717608.0.htmlRead 23 October 2026Notebookcheck spec box lists 60 Hz. Fitbit publishes no refresh rate. Treated as a stated spec, not a measurement.

Not available

Min refresh rateiLowest published display refresh rate, usually in always-on mode. It is not the active-use minimum unless stated.

Not available

Not available

Peak brightnessiMaker peak-brightness claim. It may apply to a small area or bright ambient light. Full-screen limits and battery/temperature conditions belong in source notes.

1,000nits12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Display brightness: Up to 1,000 nits. Fitbit publishes no nit figure in the documents read, so this is a spec database claim. Window size and ambient conditions are not stated.

2,500nits1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026HBM brightness 1500 nits and peak brightness 2500 nits. The maker says HBM is the highest brightness with the whole screen lit and peak is for a specific area. No reviewer measurement is substituted.

Minimum brightness

Not available

Not available

Always-on display

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Adjust always-on display section. The setting reduces battery life.3Maker product pagestore.google.com/us/product/fitbit_sense_2Read 23 October 2026Always-on display mode: keeps your display on at all times (may require more frequent charging).

Yes2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026Battery table gives a 9 day AOD scenario. The FAQ explains the AOD setting.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Display Q4: Always-on display setting with a schedule. It reduces battery life.

Display cover

Gorilla Glass2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Display: Corning Gorilla Glass 3.

Other glass3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026

Display cover (as published)

Corning Gorilla Glass 32Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Display: Corning Gorilla Glass 3.

2D flat tempered high-aluminosilicate glass, 9H pencil hardness3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Screen Q1: 2D high-aluminosilicate glass with 9H pencil scratch hardness. Body Q3: 2D flat tempered glass cover. No brand is named.

Platform

9 of 15 differ

Platform

Proprietary2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026No OS name is printed on the spec page. The Fitbit blog says the watch is powered by the new Fitbit OS, a proprietary platform with its own Gallery.

Proprietary1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Operating system: Xiaomi HyperOS 3, Xiaomi's own software. No Wear OS or other third-party watch platform is named.

OS at launch

Fitbit OS4Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 23 October 2026Powered by the new Fitbit OS. No version number is published.

Xiaomi HyperOS 31Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Software

Not available

Not available

Latest OS

Fitbit OS, firmware 220.317Maker product pagesupport.google.com/googlehealth/answer/14236725Read 23 October 2026Fitbit firmware release notes: Sense 2 latest listed version 220.31 (bug fixes and improvements) on the access date. No Fitbit OS major version number is published.

Not available

Works with

iOS, Android2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Requirements: Apple iOS 16.4 or higher, Android OS 11.0 or higher, current on the access date.

Android, iOS1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Android 8.0 and above, or iOS 14.0 and above.

Phone requirement

Google Health app on a compatible device running Apple iOS 16.4 or higher or Android OS 11.0 or higher2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Requirements: the Google Health app on a device running Apple iOS 16.4 or higher or Android OS 11.0 or higher. This is the current requirement. The 2022 launch requirement may have been lower.

Android 8.0 and above, or iOS 14.0 and above, with the Mi Fitness app3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Connect and Pair Q1: the watch needs the Mi Fitness app on iOS or Android.

App store

No1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026The Fitbit Gallery offers Fitbit apps and clock faces. Tom's Guide states third-party apps cannot be downloaded.17Reviewtomsguide.com/news/fitbit-sense-2Read 23 October 2026Review: you don't get access to third-party apps. You can download custom watch faces but not third-party apps. The Sense 2 and Versa 4 cannot.

No3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Apps Q1: installing third-party apps is not supported.

Voice assistants

Amazon Alexa1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Voice Assistant: Amazon Alexa Built-in. Needs the phone app running in the background. Not available in all countries.3Maker product pagestore.google.com/us/product/fitbit_sense_2Read 23 October 2026Smarts and more: Alexa Built-in.

Not available

Chipset

Ambiq Apollo4 Plus12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Platform: Ambiq Apollo4 Plus, ARM Cortex-M4 at 96-192 MHz. Fitbit publishes no chip and Notebookcheck says it does not disclose the SiP. Ambiq's own presentation says Apollo4 powers the Sense product line, which supports the chip family but not the Plus suffix.16Press articleambiq.com/wp-content/uploads/2022/12/Key-to-the-Future-of-Electronics.pdfRead 23 October 2026Ambiq presentation: Apollo4 powers Inspire, Versa and Sense product lines of Fitbit, and Versa 4, Sense 2 and Inspire 3 were launched in August 2022.

BES2800BP3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026System Q1: processor BES2800BP with HyperOS, factory version 3.220.063.

Process

Not available

Not available

CPU cores

112Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Same Platform entry: one ARM Cortex-M4 core.

Not available

CPU configuration

AFitbit Sense 2

Count	Core	Max clock (GHz)
1	Arm Cortex-M4	0.192

Source12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Same Platform entry: ARM Cortex-M4 at 96-192 MHz. 192 MHz is stored as the maximum.

BXiaomi Watch S5 46mm

Not available

Max CPU clock

0.192GHz=CalculatedFrom CPU configuration

Not available

GPU

Not available

Not available

Low-power coprocessor

Not available

Not available

Memory

1 of 2 differ

RAMiKeep published GB values as stated. Convert a source explicitly labelled MB using 1000 MB per GB and preserve its original figure and unit in the note. Do not assume MB means MiB. Convert explicit MiB or GiB to decimal GB through their byte definitions, recording the conversion in the note. This normalization does not establish an exact physical byte count.

2.75 MB12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Same entry: 2.75 MB on-chip SRAM, stored as 0.00275 GB with 1000 MB per GB. No maker figure exists.

Not available

StorageiTotal built-in storage the maker states, in decimal GB. Space available to the user is lower and goes in the source note. A figure the maker gives only as available space is not stored.

4GB18Measurementnotebookcheck.net/Fitbit-Sense-2-Smartwatch-review-Automatic-activity-recording.717608.0.htmlRead 23 October 2026Performance and runtime: the manufacturer has installed 4 GB of internal storage, usable for apps and watch faces. Fitbit publishes no storage figure. Routes and music cannot be stored.

4GB3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026System Q7 says RAM 64 GB and ROM 4 GB. The RAM figure cannot be right for a watch and is not stored. The 4 GB ROM matches the Amazon US spec table.15Retailer pageamazon.com/dp/B08N64F336Read 20 October 2026Amazon US listing for the Black BHR08IVGL: memory storage capacity 4 GB. Listed by a marketplace seller. Xiaomi has no official US release.

Health sensors

6 of 8 differ

Heart rate sensor

Multi-path optical heart rate sensor1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: multi-path optical heart rate tracker. The Google Store spells it Multi-path optical heart rate sensor.2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Sensors and components: multi-path optical heart rate sensor.

Four-LED, four-PD optical heart rate and blood oxygen sensor1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Sensors row: heart rate sensor with blood oxygen sensor. The overview page and FAQ name a four-LED, four-PD design.

ECG capabilityiElectrical heart sensing hardware with an ECG capability. The ECG app can require an eligible country, age and paired phone.

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: multipurpose electrical sensors compatible with the ECG app and EDA Scan app. The ECG app is not available in all countries.2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Sensors: multipurpose electrical sensors compatible with ECG app and EDA app. ECG not available in all countries.

No3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Heart Q3: mobile ECG atrial fibrillation alerts are not supported. Gadgets and Wearables also lists ECG as No.10Spec databasegadgetsandwearables.com/technical-specs/xiaomi-watch-s5-46mmRead 20 October 2026Spec table: ECG No.

Blood oxygen sensingiBlood-oxygen sensing capability. App availability and medical status vary by market.

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: red and infrared sensors for oxygen saturation (SpO2) monitoring.

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Skin temperature sensingiA sensor or supported function that measures skin temperature. It is not a core-body thermometer.

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: on-wrist skin temperature sensor. Track your skin temperature changes: nightly variation from a personal baseline. Not available in all markets.

No3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Body temperature Q1: body temperature measurement is not supported.10Spec databasegadgetsandwearables.com/technical-specs/xiaomi-watch-s5-46mmRead 20 October 2026Spec table: skin temperature No.

Blood pressure featureiPublished blood-pressure feature category. Hypertension notifications are not numerical blood-pressure readings.

None12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Blood pressure: No. The maker sensor list and feature pages have no blood-pressure feature.

None3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Support answers say blood pressure measurement is not supported.

Body composition sensor

No1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026The complete sensor list in Sensors and Components has no bioelectrical impedance sensor.12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Body composition: No.

Not available

Skin conductance (EDA)

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: electrical sensor to measure skin conductance (cEDA) for stress detection. Manage stress: continuous EDA identifies body responses.4Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 23 October 2026Sense 2 has a new Body Response sensor for continuous electrodermal activity (cEDA).

Not available

Medical clearancesiNamed regulatory clearances and their jurisdiction. General water resistance or an ECG sensor does not establish medical clearance.

ECG app: FDA clearance, ECG app: EU clearance, Irregular Heart Rhythm Notifications: FDA clearance, Irregular Heart Rhythm Notifications: EU clearance3Maker product pagestore.google.com/us/product/fitbit_sense_2Read 23 October 2026Heart section: the ECG app assesses heart rhythm for atrial fibrillation. Clearance wording is in the Fitbit blog.5Press releaseblog.google/products-and-platforms/devices/fitbit/fitbit-sense-2-versa-4Read 23 October 2026Footnote and text: the ECG app on Sense 2 and the Irregular Heart Rhythm Notifications on both watches have FDA and EU clearance. Only in select countries, not for people under 22 or with known atrial fibrillation.

Not available

Motion and environment sensors

1 of 9 differ

Accelerometer

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: 3-axis accelerometer.2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Sensors and components: 3-axis accelerometer.

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Accelerometer range

Not available

Not available

Gyroscope

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: gyroscope.

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Barometric altimeter

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: altimeter, which tracks altitude changes.

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Compass

No1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026The complete sensor list in Sensors and Components has no compass or magnetometer. Gadgets & Wearables also lists Compass: No.12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Compass: No. Geomagnetic: No.

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Ambient light sensor

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: ambient light sensor.

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Sensors row lists an ambient light sensor.

Depth gauge

Not available

Not available

Depth gauge rangeiPublished measurement range of the depth gauge, distinct from maximum diving depth and water-pressure resistance.

Not available

Not available

Water temperature sensor

Not available

Not available

Health and fitness

3 of 5 differ

Health featuresiSupported health functions with country, phone and subscription restrictions in the source notes. Upcoming functions are not counted as available.

Continuous heart rate, Heart rate alerts, Irregular rhythm notifications, ECG app, Blood oxygen app, Heart rate variability, Sleep tracking, Sleep stages, Stress tracking, Readiness score, Cycle tracking1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Today and sleep sections: sleep stages (REM, light, deep) and sleep score, stress management score, readiness score (Premium), menstrual health tile, high and low heart rate notifications after 10 inactive minutes, heart-rate variability under Advanced health metrics, oxygen saturation. Daily readiness score needs Fitbit Premium. Irregular rhythm notifications and the ECG app come from the Fitbit blog.3Maker product pagestore.google.com/us/product/fitbit_sense_2Read 23 October 2026Heart rate tracking, high and low heart rate notifications, irregular heart rhythm notifications, ECG app, HRV, breathing rate, SpO2, sleep tracking and sleep stages, Stress Management Score, Daily Readiness Score, menstrual health tracking. The Daily Readiness Score is a Premium feature in the manual.

Continuous heart rate, Heart rate alerts, Blood oxygen app, Heart rate variability, Sleep tracking, Sleep stages, Stress tracking, Cycle tracking2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026Overview: 24/7 heart rate, all-day blood oxygen, all-day stress, women's health cycle tracking and advanced sleep monitoring. These are not medical features.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Heart, SpO2, stress, cycles and sleep answers: sustained high and low heart rate alerts, all-day SpO2 and stress, sleep HRV, sleep stages (deep, light, REM) and menstrual cycle tracking. Smart period prediction is not supported.

Fitness featuresiSupported workout functions. A sport-profile name alone does not prove advanced metrics such as running power or running dynamics. Trackback follows the recorded route back to the start. A compass arrow that points straight to the start does not count.

Automatic workout detection, VO2 max, Pool swim, Interval workouts, Turn-by-turn navigation1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Exercise settings list Pool Length, Interval, Auto Start and Auto-Stop. Track your exercise automatically (SmartTrack, 15 minute minimum). Google Maps gives turn-by-turn directions and needs the paired phone nearby with the app running. View your cardio fitness score (stored as vo2_max, see the Google Health VO2 max help page).3Maker product pagestore.google.com/us/product/fitbit_sense_2Read 23 October 2026Fitness features: Cardio Fitness Score estimated from VO2 max, SmartTrack Automatic Exercise Recognition (in app only), Google Maps turn-by-turn directions.11Maker product pagesupport.google.com/googlehealth/answer/14237924Read 23 October 2026Learn about your VO2 max: VO2 max, formerly the cardio fitness score, is estimated during outdoor runs with GPS. The Sense 2 manual names the cardio fitness score.

Automatic workout detection, VO2 max, Training load, Running dynamics, Pool swim, Open water swim, Route navigation2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026Overview: running form recognition (vertical ratio, vertical oscillation, ground contact time), 150+ sport modes and offline route navigation. Backtracking is described but not stored as trackback because the method is not stated.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Workout answers: auto detect for running, cycling, rower, elliptical, jump rope and walking, fitness level and VO2 max, training load, wrist running form (vertical ratio, vertical amplitude, ground contact time) for outdoor and track running, pool swimming, open water and route navigation with Start navigation.

Sport profilesiPublished count of distinct sport/activity profiles. A claim such as 180+ is not an exact integer count.

Not available

Not available

Dive modesiActual supported dive modes. Water resistance or a depth app alone does not establish decompression-capable scuba support.

Not available

Not available

External sensorsiTypes of external workout sensors the watch can pair with. GPS reception, phone data and built-in sensors do not qualify.

Not available

Power meter2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026Overview: Bluetooth power meters that use standard Bluetooth protocols are supported. Bluetooth heart rate broadcasting sends the watch's own rate to a bike computer.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Workout Q6: only power meters that use standard Bluetooth protocols.

Safety

3 of 6 differ

Fall detectioniAutomatic fall detection. Incident detection restricted to recorded workouts is not counted as general fall detection.

No9Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 23 October 2026Safety and emergency rows (Safety Check, Emergency Sharing, Medical information, Fall Detection, Emergency SOS, Emergency international calling, Car Crash Detection, Earthquake Alerts): the Sense 2 column is empty for all of them. No fall detection.

Yes3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Security Q2: with Emergency SOS and Fall detection on, a serious fall followed by 60 seconds of inactivity dials the emergency contact and texts the location.

Car crash detection

No9Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 23 October 2026Same Safety rows: Car Crash Detection is empty in the Sense 2 column.

Not available

Emergency SOSiA manual emergency alert to emergency services or preset contacts. Source notes identify the recipient, paired-phone requirement and country limits. Satellite is listed separately.

No9Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 23 October 2026Same Safety rows: Emergency SOS is empty in the Sense 2 column.

Yes3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Security Q1: press the power button three times to call the emergency contact and send your location. Up to 3 contacts. It needs the Mi Fitness app setup and a paired phone.

Emergency sireniPublished or measured siren sound level in decibels. Audible distance alone does not establish this value. Measurement distance belongs in source notes.

Not available

Not available

Live location sharingiShares live location during supported use. A paired phone or data subscription may be required.

Not available

Not available

Dedicated LED flashlightiA dedicated hardware LED flashlight. Lighting the display white is not counted.

No9Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 23 October 2026No flashlight appears in the Sense 2 sensor and component list. Gadgets & Wearables states Flashlight: No.12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Flashlight: No.

No3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026The Control center flashlight turns the screen into a white light. There is no LED.

Positioning

3 of 3 differ

PositioningiPublished satellite systems and signal bands. Do not infer bands from dual-frequency support alone.

GPS, GLONASS1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: built-in GPS receiver + GLONASS. Dynamic GPS can use the phone's GPS instead to save battery. No band or dual-frequency claim.4Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 23 October 2026Built-in GPS is named for Sense 2.

GPS, Galileo, GLONASS, BeiDou, QZSS1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026GPS, Galileo, Glonass, BeiDou and QZSS. The overview page says dual-band five-system GNSS.

Dual-band GNSSiMaker-stated dual-frequency satellite reception. Supported constellations and signal bands are listed separately.

Not available

Yes2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026Upgraded dual-band five-system GNSS with an all-new dual-frequency positioning chip.

Offline mapsiMap data stored on the watch and usable without live phone data. GPX routes or breadcrumb tracks alone are not offline maps.

No12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Offline maps: No. The manual requires the phone and background app for Google Maps.

Yes2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026Full-colour offline maps with route navigation. Maps must be downloaded through the Mi Fitness app. Availability may vary by region.

Connectivity

5 of 15 differ

BluetoothiPublished Bluetooth support for this model. The version is recorded separately. Unknown version does not mean the radio is absent.

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Wireless technology: Bluetooth 5.0 radio transceiver and NFC chip.

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026

Bluetooth version

5.01Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Wireless technology, printed page 62: Bluetooth 5.0 radio transceiver and NFC chip.14Spec databasenextpit.de/smartwatches/google-fitbit-sense-2Read 23 October 2026Bluetooth: 5.

5.41Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Dual-mode Bluetooth BLE/BT 5.4.

Wi-FiiPublished Wi-Fi support for this model. The standard and bands are recorded separately. Unknown standard does not mean Wi-Fi is absent.

No1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components: WiFi (deactivated, cannot be turned on). Stored as false because the user cannot use it. No Wi-Fi standard is stored.

Yes3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Connectivity Q6: the watch can join Wi-Fi on its own. It cannot download apps. The Wi-Fi standard and bands are not stated.

Wi-Fi standard

Not available

Not available

Wi-Fi bands

Not available

Not available

CellulariTrue when a cellular edition is sold. A variant row states whether that individual model has cellular hardware.

No1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026No cellular radio is listed in Wireless technology (Bluetooth and NFC only).

No4Maker spec sheet (PDF)i02.appmifile.com/257_operatorx_operatorx_xm/29/08/2026/b4c07745b195e649523c370b72bc9ae7.pdfRead 20 October 2026The standards list covers Bluetooth and Wi-Fi 2.4 GHz, GNSS and NFC and has no cellular standard. GSMArena says only a separate eSIM model has cellular.

Network

Not available

Not available

4G bandsiPublished LTE bands for the stated regional cellular model. Do not transfer bands to another region or Wi-Fi-only model.

Not available

Not available

5G bandsiPublished 5G NR bands for the stated regional cellular model. RedCap support does not establish conventional full-bandwidth phone 5G.

Not available

Not available

NFCiSome regions sell an NFC edition, so it is per variant.

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Wireless technology: NFC chip. Contactless Payments section describes the built-in NFC chip.

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026NFC supported. The maker says availability may vary by region.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026NFC Q1: full hardware support. Services are limited at launch to Visa and Mastercard cards in Europe through Xiaomi Pay and EasyCard in Taiwan. More regions will follow by update.

Contactless payments

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Contactless Payments: set up Google Wallet in the Fitbit app and pay at contactless terminals.3Maker product pagestore.google.com/us/product/fitbit_sense_2Read 23 October 2026Smarts and more: Google Wallet, make purchases from your wrist everywhere Google Pay is accepted.

Yes2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026NFC payments at Mastercard and Visa terminals. Availability varies by region.

Payment services

Google Wallet1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Contactless Payments: Google Wallet. The text also names Fitbit Pay for the older service name.

Xiaomi Pay3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026NFC answers: bank cards are added through Xiaomi Pay.

Ultra-wideband

No1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Wireless technology lists only a Bluetooth radio and an NFC chip. No UWB radio.

Not available

Satellite

None9Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 23 October 2026No satellite feature in any Safety row. Published radios are Bluetooth and NFC. GPS reception is separate.

Not available

ANT+

Not available

Not available

Audio

1 of 4 differ

Speaker

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Sensors and Components lists Speaker and Microphone. The Google Store rates the speaker at 75 dB SPL at 10 cm. That is not an emergency siren.

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Specs row: Speaker supported. The microphone is also listed as supported, with no count.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Connectivity Q2: audio output switches back to the watch speaker.

Microphones

Not available

Not available

Calls on the watchiVoice-call capability of the marketed model, including sold cellular editions. Variant radio capability and paired-phone requirements still apply.

Phone only1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Answer or reject phone calls and Take on-wrist phone calls: calls go through the paired iPhone or Android phone, which must be nearby with the Fitbit app running. No cellular model exists.

Phone only3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Calls Q3: answer, end and make calls on the watch over the paired phone's Bluetooth connection. Bluetooth earbuds cannot be used for calls.

Music on the watchiPlays audio stored on the watch. Remote control of phone playback or streaming alone does not qualify.

No12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026On-board music storage: No. Smartphone music control only.

Yes3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Music Q3: MP3 files are imported through the Mi Fitness app and played on the watch.

Controls

3 of 5 differ

ButtonsiPhysical controls used to operate the watch, excluding the rotating crown and strap-release buttons. A clickable rotating crown is counted only in Crown.

11Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Navigate Sense 2: color AMOLED touchscreen display and 1 button.

13Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Body Q2 and Q3: the 4 o'clock power button is the only button. The 2 o'clock crown is counted only in Crown.

Named operating buttonsiNames of operating buttons, excluding the crown and strap-release controls.

Button1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Navigate Sense 2: the single button opens the apps menu, returns to the clock face and has long-press and double-press shortcuts.

Power button (4 o'clock)3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Body Q3: power button at 4 o'clock.

CrowniA crown that rotates to control the interface. A round push button that does not rotate is not a crown.

None1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Navigate Sense 2 describes only the touchscreen and 1 button. No crown.

Rotating3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Body Q2: a rotating crown at 2 o'clock to navigate, press for the app list.

Rotating bezeliPhysical rotation or touch gestures around the display edge. A fixed decorative bezel is None.

None1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Navigate Sense 2 describes only the touchscreen and 1 button. No bezel control.

None3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Bezel Q1: the bezel is fixed to the frame and cannot be replaced. The maker describes no bezel input.

Gestures

Turn your wrist, Briefly cover the watch face with your opposite hand, Triple-tap the screen1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Screen wake setting: Button & motion turns the screen on when you turn your wrist. Turn off the screen: briefly cover the watch face with your opposite hand, except with always-on display. Screen Zoom: Magnify works on a triple-tap.

Raise to wake, Snap fingers, Shake wrist, Rotate wrist2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026Overview: smart gesture recognition, wrist mode and quick gestures. The FAQ names the gestures.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Raise to wake appears in the Control center. Quick gestures: snap fingers, shake wrist and rotate wrist.

Battery and charging

9 of 13 differ

Battery capacityiPublished battery capacity for the stated case size. Rated and typical capacity are distinguished in source notes.

162mAh12Spec databasegadgetsandwearables.com/technical-specs/fitbit-sense-2Read 23 October 2026Battery: rechargeable lithium-polymer battery, 162 mAh.13Retailer pageifixit.com/products/fitbit-sense-2-batteryRead 23 October 2026iFixit replacement battery listing for Sense 2: 0.62 Wh, 3.87 V, 162 mAh. 162 mAh x 3.87 V = 0.627 Wh, which agrees. It is a parts listing, not a teardown. Gadgets & Wearables, Notebookcheck and nextpit also state 162 mAh. Two Argos listings print 260 mAh, which is not used.14Spec databasenextpit.de/smartwatches/google-fitbit-sense-2Read 23 October 2026Batteriekapazität (Netto): 162 mAh.

815mAh1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Capacity 815 mAh, lithium-ion polymer. Rated or typical is not stated.

Claimed battery lifeiMaker endurance claims with distinct operating modes and case sizes. With solar describes augmentation of that estimate, not hardware capability. Use false for ordinary claims without solar augmentation, true for explicitly solar-aided claims, and omit it when solar qualification is unclear. Source notes state AOD, GNSS, music and solar conditions. Do not create a normal-use row from an AOD-only claim. Low power denotes the maker battery-saver mode. Keep its typical, light-use and always-on claims separate from standard-mode claims. GPS power saving identifies an intermediate reduced-accuracy GNSS saving preset. Source notes retain the maker's preset name and published conditions. Max battery GPS is the distinct maximum-saving claim. When the maker has only one GPS saving preset, it is GPS power saving.

AFitbit Sense 2

Mode	With solar	Hours (h)
Smartwatch	No	144
Always-on	No	72
GPS	No	5

Source2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Battery and power: battery life of 6+ days, stored as 144 h as a minimum figure. Up to 5 hours with continuous GPS, stored as the gps row. The always-on display, SpO2 and cEDA sensor need more frequent charging. The Google Health support article states up to 12 hours with continuous GPS for Sense 2, a conflict. The model spec page is used because the Oct 2022 Fitbit.com page printed the same 5 hours.6Maker product pagesupport.google.com/googlehealth/answer/14226518Read 23 October 2026Estimated battery life table: Fitbit Sense 2 6+ days. Footnote: with always-on display, Sense 2 has a battery life of up to 3 days (stored as 72 h always_on). The same footnote says Sense 2 has up to 12 hours with continuous GPS, which conflicts with the 5 hours on the model spec page. The 12 hour figure is not stored.10Maker product pageweb.archive.org/web/20221022073607/https://www.fitbit.com/global/us/products/smartwatches/sense2Read 23 October 2026Archived Fitbit.com Sense 2 page, Oct 22, 2022: battery life of 6+ days and up to 5 hours with continuous GPS. Same wording as the current Google Store.

BXiaomi Watch S5 46mm

Mode	With solar	Hours (h)
Smartwatch	No	336
Always-on	No	216
Light use	No	504

Source2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026Up to 21 days in the light usage scenario, 14 days normal and 9 days with AOD, tested by Xiaomi Internal Labs. Days are converted exactly to hours. The FAQ gives the full test conditions.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Charging Q4: up to 21 days in the maximum scenario with power-hungry monitoring off and no AOD, 14 days in the typical scenario and 9 days with AOD. Test conditions include 100 messages a day and 15 minutes of Bluetooth calls a week.

Smartwatch mode (claimed)iMaker normal-use smartwatch claim without solar. A watch with only an explicit AOD-mode claim has no value here. Workloads differ and source notes must be read.

144h=CalculatedFrom Claimed battery life

336h=CalculatedFrom Claimed battery life

AOD battery life (up to)iMaker claimed smartwatch endurance with the always-on display enabled and without solar, for the base case. Source notes preserve workload and case conditions. This is a claim, not a measured test or an AOD-off estimate.

72h=CalculatedFrom Claimed battery life

216h=CalculatedFrom Claimed battery life

GPS mode (claimed)iMaker regular GPS/GNSS activity claim without solar, for the base case. AOD, multi-band, music and power-saving conditions have separate rows when published.

5h=CalculatedFrom Claimed battery life

Not available

Solar chargingiPublished solar charging hardware capability. An ordinary battery estimate without solar augmentation does not prove that the watch lacks solar charging hardware.

Not available

Not available

Charging methodiThe connection at the watch, not the cable end at the USB adapter. A proprietary inductive puck is not Qi unless interoperability is explicitly established.

Magnetic pins1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Charge your watch: hold the cable end near the port on the back until it attaches magnetically. The pins on the cable align with the port on the back.

Magnetic pins1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Charging port: 2-pin magnetic charging dock.

Charging guidanceiPublished charging requirements, nominal estimates and compatibility guidance. Keep adapter ratings separate from power accepted by the watch.

Not available

2-pin magnetic charging dock with a USB cable. Xiaomi gives 5 V and 2 A wired charging and asks for a USB-A adapter with 5 V and 2 A output. Wireless charging is not supported. Charging works from 1 to 45 C.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Charging Q1, Q2, Q3 and Q9: 5 V and 2 A wired charging, USB-A adapter with 5 V and 2 A, no wireless charging, dock shared with Watch S2, S3 and S4.

Max charging power (watch)iPublished maximum charging power at the watch. Adapter rating or charger input power does not prove the power accepted by the watch.

Not available

Not available

Fast chargingiAn explicit fast-charging capability claim. A short charging time or high adapter wattage alone does not qualify.

Yes5Press releaseblog.google/products-and-platforms/devices/fitbit/fitbit-sense-2-versa-4Read 23 October 2026Fast charging gets a full day's worth of battery in just 12 minutes.

Not available

Quick charge claimiMaker claim for usage from a short charge. Source notes identify the usage workload, such as normal use or sleep tracking.

Charge time12 minUse time24 h1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Charge your watch: charge Sense 2 for 12 minutes for 24 hours of battery life. The usage workload is not named.

Not available

Charge 0 to 80% (claimed)iMaker claim for charging an empty battery to 80%. Charger and approximate qualifiers belong in source notes.

Not available

Not available

Full charge time (claimed)iMaker advertised nominal full-charge duration. Approximate or theoretical maker estimates are allowed, with their conditions in source notes. Partial-charge intervals do not qualify. Measured 0 to 100% tests have a separate field.

120min1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Charge your watch: charging fully takes about 1-2 hours. The Google Store spec page states two hours and is stored.2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026Battery and power: the Oct 2022 Fitbit.com spec text states charge time (0-100%): two hours.

90min3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Charging Q4 and Q7: about 90 minutes to fully charge with the official dock and a 5 V and 2 A or higher adapter.

Measured

3 of 4 differ

Peak brightness (measured)iReviewer measurement. Source notes state screen area, mode and ambient light. A small-area peak claim cannot be replaced with a full-screen measurement.

Not available

Not available

Battery life (measured)iReviewer-observed mixed-use endurance. Source notes state case size, AOD, workout use and whether it was a complete discharge. Extrapolation from partial discharge is excluded.

144h18Measurementnotebookcheck.net/Fitbit-Sense-2-Smartwatch-review-Automatic-activity-recording.717608.0.htmlRead 23 October 2026Battery life: with all measurements active, worn around the clock, automatic training detection on, no extensive workouts and the always-on display off, the Sense 2 lasts exactly six days (144 h). Firmware and brightness are not stated. The always-on display test (just under four days) has no exact figure and is not stored.

Not available

Battery tests (measured)iReviewer-observed endurance, with case size and test settings in source notes. Partial-discharge projections are not stored as measured endurance.

AFitbit Sense 2

Test	Hours (h)
Mixed use, always-on display off	144

Source18Measurementnotebookcheck.net/Fitbit-Sense-2-Smartwatch-review-Automatic-activity-recording.717608.0.htmlRead 23 October 2026Same test: always-on display off, all measurements active, automatic training detection, no extensive workouts. 6 days converted to 144 h. With the always-on display on it lasted just under four days, which is not stored as a number.

BXiaomi Watch S5 46mm

Test	Hours (h)
Mixed use, display setting unspecified	360

Source7Reviewgsmarena.com/xiaomi_watch_s5_review-news-73952.phpRead 20 October 2026Review of 11 October 2026: 15 days of endurance from a single charge with raise-to-wake active, five workouts a week and daily sleep tracking. Display mode is not stated and AOD was not tested separately. Stored as 360 h. No full-discharge log is shown.

Full charge time (measured)iReviewer measurement from empty to full, not 0-80% or a charge from 5%. Source notes name the charger and case size.

95min18Measurementnotebookcheck.net/Fitbit-Sense-2-Smartwatch-review-Automatic-activity-recording.717608.0.htmlRead 23 October 2026Battery life: 0 to 99 percent after 85 minutes on a 24-watt power supply and another 10 minutes for the last percent. Stored as 95 minutes for 0 to 100 percent. 0 to 80 percent took one hour. Test unit with the supplied charging cable and a 24 W adapter. The maker claims two hours.

Not available

Strap

5 of 6 differ

Lug widthiDistance between standard strap attachment lugs, not the decorative width of a proprietary strap. Unknown for custom connectors unless the maker publishes lug width.

24mm3Maker product pagestore.google.com/us/product/fitbit_sense_2Read 23 October 2026The store shows an accessory shop headed Shop 24mm attach accessories. Fitbit publishes no lug width in a spec table, and the connector is proprietary, so this is the maker's attach size only.18Measurementnotebookcheck.net/Fitbit-Sense-2-Smartwatch-review-Automatic-activity-recording.717608.0.htmlRead 23 October 2026Case and features: the strap is 24 millimeters wide and can be changed without tools. It is not a standard clasp, so 24 mm is the strap width, not a lug width for standard straps.

22mm3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Strap Q6: 22 mm strap width.

Quick-release strapiThe supplied strap can be detached through its quick-release mechanism. Compatibility with quick-release replacement straps alone does not qualify.

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Change the band: slide the flat latch button toward the band, pull the band away. Attach by pressing until it clicks. No tools.

Yes3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Strap Q6, Q8 and Q9: the quick-release strap is removed with a slide lever.

Strap systemiPublished attachment system and compatible case sizes. Proprietary connectors are distinguished from standard spring bars.

Proprietary latch connector. Fitbit Sense, Versa 3 and Versa 4 bands are compatible.1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Change the band: Fitbit Sense, Fitbit Versa 3, and Fitbit Versa 4 bands are compatible with Sense 2. Band latches on the back. No lug width is stated in the manual.

22 mm quick-release straps3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Strap Q6: compatible with watches that support 22 mm straps.

Strap materialiMaterial of the supplied strap for the stated package. Do not substitute material from another band sold separately.

Other1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Materials: the supplied band is a flexible, durable elastomer similar to the material used in many sports watches. Other preserves that wording without guessing silicone, HNBR or fluoroelastomer.

Fluoroelastomer1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Black: fluororubber strap. Fluororubber is stored as fluoroelastomer.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Strap Q7: fluororubber for Black and Silver, leather for Ceramic Blue and fluororubber nylon braided for forged carbon Jungle Green. The Jungle Green strap fits no single enum option and is stored as other.

Strap

Classic band2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026What's in the box: Classic band (Small and Large).

Black fluororubber strap1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Strap rows by colour. The Black version has a black fluororubber strap.3Maker product pagemi.com/global/support/faq/details/KA-703529Read 20 October 2026Strap Q6: black fluororubber, gray fluororubber, blue leather and green fluororubber nylon braided.

Strap sizesiPublished wrist-circumference range for the stated strap or case. Source notes distinguish an overall compatible wrist range from one supplied strap size.

AFitbit Sense 2

Size	Wrist (min) (mm)	Wrist (max) (mm)
Small	140	180
Large	180	220

Source1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Band size, printed page 63: Small band fits a wrist of 140 to 180 mm (5.5 to 7.1 in), Large band 180 to 220 mm (7.1 to 8.7 in). The Google Store page prints different ranges (130 to 180 mm and 165 to 220 mm). The manual is preferred. These are the supplied straps.

BXiaomi Watch S5 46mm

Size	Wrist (min) (mm)	Wrist (max) (mm)
Black fluororubber strap	140	210

Source1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Black and Silver fluororubber straps have an adjustable length of about 140 to 210 mm. The maker publishes strap length, stored as the wrist range. Ceramic Blue leather and Jungle Green straps are about 135 to 205 mm.

Regulatory

1 of 3 differ

FCC ID

XRAFB5211Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026USA FCC statement: Model FB521, FCC ID XRAFB521.

Not available

SAR limb (US)iPublished limb/wrist SAR for the stated base regional model under the US regime. Other case sizes or radio versions can differ. Head or body SAR is excluded.

Not available

Not available

SAR limb (EU)iPublished limb/wrist SAR for the stated base regional model under the EU regime. Other case sizes or radio versions can differ. Head or body SAR is excluded.

Not available

Not available

Other certifications

RED (2014/53/EU), UK Radio Equipment Regulations 2017, IEC 62368-1:2014, IEC 62368-1:2020 + A11:2020, ISED Canada (IC: 8542A-FB521)1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026EU section: Fitbit LLC declares Model FB521 compliant with Directive 2014/53/EU. UK section: Radio Equipment Regulations 2017. Safety Statement lists IEC 62368-1:2014 and IEC 62368-1:2020 + A11:2020. Canada section lists IC 8542A-FB521. These are model declarations, not medical, military or diving certifications.

EU RED 2014/53/EU conformity, RoHS 2011/65/EU conformity4Maker spec sheet (PDF)i02.appmifile.com/257_operatorx_operatorx_xm/29/08/2026/b4c07745b195e649523c370b72bc9ae7.pdfRead 20 October 2026The declaration covers RE Directive 2014/53/EU and RoHS Directive 2011/65/EU.

In the box

1 of 2 differ

In the box

Fitbit Sense 2, Classic band (small & large), Charging cable1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026What's in the box: watch with small band, charging cable and an additional large band.2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026What's in the box: Fitbit Sense 2 Classic band (Small and Large), charging cable.

Xiaomi Watch S5 46mm, Magnetic charging dock, User manual (including warranty notice)1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Package contents: watch, magnetic charging dock, user manual with warranty notice.

Power adapter in boxiA mains/USB power adapter is supplied. A charging cable, inductive puck or charging dock alone does not count.

No1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026What's in the box lists the watch, bands and the charging cable. No power adapter. The cable plugs into a USB port or a UL-certified USB wall charger.

No1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Package contents list no power adapter.

Links

Not compared

Product page

store.google.com/us/product/fitbit_sense_23Maker product pagestore.google.com/us/product/fitbit_sense_2Read 23 October 2026Google Store product page for Fitbit Sense 2 (US).

www.mi.com/global/product/xiaomi-watch-s5-46mm2Maker product pagemi.com/global/product/xiaomi-watch-s5-46mmRead 20 October 2026

Spec sheet

store.google.com/us/product/fitbit_sense_2_specs2Maker product pagestore.google.com/us/product/fitbit_sense_2_specsRead 23 October 2026This page is the maker's technical specs page for Sense 2.

www.mi.com/global/product/xiaomi-watch-s5-46mm/specs1Maker product pagemi.com/global/product/xiaomi-watch-s5-46mm/specsRead 20 October 2026Global specs page. The base values describe the Black version with its black fluororubber strap.

Manual

storage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0d1Owner's manualstorage.googleapis.com/support-kms-prod/Cxknk8y9NHEphUUIYGTQvRVIFq1RZyQuGQ0dRead 23 October 2026Fitbit user manual, version 3.1, hosted on the Google Health Help Center user manuals page.

Not available

EPREL registration numberiId in the EU energy label database. Each size or model of a series has its own id, so it is per variant.

Not available

Not available

Warranty

1 of 1 differ

Manufacturer warranty (source market)iThe maker's warranty period for the exact SKU or configuration and market named in the source note. It applies only to that stated market, not every regional variant. Statutory consumer rights are excluded. The base term is stored. An extension that needs registration goes in the source note.

1year8Maker product pagesupport.google.com/product-documentation/answer/14815834Read 23 October 2026Fitbit Limited Warranty: new products carry one year from purchase, two years for EEA residents who bought in the EEA. Devices bought on or after July 11, 2023 fall under the Google Hardware Warranty Center terms. Stored as the US one-year term.

Not available

Both are also in the API. Back to all smartwatches.