Smartwatches / Compare

Amazfit Active 2 (Square) vs Fitbit Versa 4

A

Product A: Amazfit

Active 2 (Square)

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B

Product B: Fitbit

Versa 4

89 of 150 known

Change Fitbit Versa 4

Compare the Amazfit Active 2 (Square) with

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Every value links to where we found it.

Only differences

AAmazfit Active 2 (Square)

BFitbit Versa 4

General

6 of 10 differ

Series

Active1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Listed in the Explore other Active models block

Versa3Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 6 October 2026

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

W2440GL3N, ACITVESBK-C0077035004, A2440, A2434, W2434GL2N1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026US SKU W2440GL3N2Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026EU SKU as the maker prints it: ACITVESBK-C0077035004. Retailer euronics.ie lists the black Active 2 Square as code 146-W2434GL2N, so W2434GL2N is kept as a model number without a variant row9Retailer pageeuronics.ie/products/amazfit-active-2-square-smartwatch-amoled-fitness-lifestyle-watchRead 15 October 2026Product code 146-W2434GL2N for Amazfit Active 2 Square Black. The manual names regulatory models A2434 and A2440

FB523, FB523BKBK-US, FB523SRAG-US, FB523RGRW-US, FB523RGRD1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Regulatory and Safety Notices: Model FB523 for FCC, IC, EU, UK and the IP rating. Retail colour SKUs are not stored.16Retailer pageabt.com/Fitbit-Versa-4-Graphite-Aluminum-Black-Strap-Fitness-Smartwatch-24mm-FB523BKBKUS/p/182318.htmlRead 7 October 2026Retail colour SKU FB523BKBK-US. Regulatory assembly remains FB523.17Retailer pageabt.com/Fitbit-Versa-4-Platinum-Aluminum-Waterfall-Blue-Strap-Fitness-Smartwatch-24mm-FB523SRAGUS/p/182320.htmlRead 7 October 2026Retail colour SKU FB523SRAG-US. Regulatory assembly remains FB523.18Retailer pageabt.com/Fitbit-Versa-4-Copper-Rose-Aluminum-Pink-Sand-Strap-Fitness-Smartwatch-24mm-FB523RGRWUS/p/182319.htmlRead 7 October 2026Retail colour SKU FB523RGRW-US. Regulatory assembly remains FB523.19Retailer pagephotopoint.ee/en/sports-watches/3626308-fitbit-versa-4-smart-watch-nfc-gps-satellite-amoled-touchscreen-heart-rate-monitor-activityRead 7 October 2026Retail colour SKU FB523RGRD. Regulatory assembly remains FB523.

GTIN / EAN

850071618334, 69725961088181Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026US barcode from the Shopify product feed: 8500716183342Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026EU barcode from the Shopify product feed: 6972596108818

810073611450, 810073611474, 810073611481, 81003885874616Retailer pageabt.com/Fitbit-Versa-4-Graphite-Aluminum-Black-Strap-Fitness-Smartwatch-24mm-FB523BKBKUS/p/182318.htmlRead 7 October 2026Exact FB523BKBK-US Black / Graphite Aluminum listing identifies 810073611450. Regional identifiers are not exchanged.17Retailer pageabt.com/Fitbit-Versa-4-Platinum-Aluminum-Waterfall-Blue-Strap-Fitness-Smartwatch-24mm-FB523SRAGUS/p/182320.htmlRead 7 October 2026Exact FB523SRAG-US Waterfall Blue / Platinum Aluminum listing identifies 810073611474. Regional identifiers are not exchanged.18Retailer pageabt.com/Fitbit-Versa-4-Copper-Rose-Aluminum-Pink-Sand-Strap-Fitness-Smartwatch-24mm-FB523RGRWUS/p/182319.htmlRead 7 October 2026Exact FB523RGRW-US Pink Sand / Copper Rose Aluminum listing identifies 810073611481. Regional identifiers are not exchanged.19Retailer pagephotopoint.ee/en/sports-watches/3626308-fitbit-versa-4-smart-watch-nfc-gps-satellite-amoled-touchscreen-heart-rate-monitor-activityRead 7 October 2026Exact FB523RGRD Beet Juice / Copper Rose Aluminum listing identifies 810038858746. Regional identifiers are not exchanged.

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

January 20255Press releasenasdaq.com/press-release/amazfit-expands-active-2-lineup-new-active-2-square-all-same-features-now-sleekRead 15 October 2026The release says the Active 2 Square debuted at CES 2025. The exact day is not stated

24 August 20223Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 6 October 2026Fitbit blog post dated Aug 24, 2022. Pre-orders started that day with worldwide availability this fall.

Status

Available1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Available2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026Google Store sells Versa 4 at 199.95 USD on the access date. That is a current price, not the launch price.

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

Not available

Not available

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.

$149.995Press releasenasdaq.com/press-release/amazfit-expands-active-2-lineup-new-active-2-square-all-same-features-now-sleekRead 15 October 2026Priced at USD 149.99. US price excludes tax

$229.954Press releaseblog.google/products-and-platforms/devices/fitbit/fitbit-sense-2-versa-4Read 6 October 2026Versa 4 is now available for $229.95 (USD). The Aug 24, 2022 announcement gives the same price. No euro launch price was found in a maker source.

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.

€149.95Press releasenasdaq.com/press-release/amazfit-expands-active-2-lineup-new-active-2-square-all-same-features-now-sleekRead 15 October 2026Priced at EUR 149.90, as published with VAT. The German Amazfit store lists the same price

Not available

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

US, EU1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 20262Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026EU store sells it

US, GB, DE, EE2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026US, GB and DE maker stores offer the model. EE is a documented archived Beet retail listing, not a current-stock assertion.10Maker product pagestore.google.com/gb/product/fitbit_versa_4_specsRead 7 October 2026GB store offers Versa 4 at GBP 179.99 with Buy and all four colours. Current price is not a launch price.11Maker product pagestore.google.com/de/product/fitbit_versa_4_specsRead 7 October 2026DE store offers Versa 4 at EUR 199.95 with Kaufen and all four colours. Current price is not a launch price.19Retailer pagephotopoint.ee/en/sports-watches/3626308-fitbit-versa-4-smart-watch-nfc-gps-satellite-amoled-touchscreen-heart-rate-monitor-activityRead 7 October 2026Exact Beet FB523RGRD SKU was listed by Estonian retailer with Estonia delivery. Listing is now archived. This documents historical market scope rather than current stock.

ColoursiThe maker's own colour names

Black (with additional red strap), Black Leather1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026US store option Black (with additional red strap)2Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026EU store option Black Leather

Black / Graphite Aluminum, Waterfall Blue / Platinum Aluminum, Pink Sand / Copper Rose Aluminum, Beet Juice / Copper Rose Aluminum2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026

Segment

Smartwatch1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Marketed as an everyday health and fitness smartwatch. The sport profile count is stated only as 160+

Smartwatch2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026Page title: Fitbit Versa 4 Smartwatch. The Aug 24, 2022 Fitbit blog calls it a fitness 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

Not available

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.

36.9mm1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Compare block lists a 36.9mm case width. The square case has no diameter, so this is the case width

Not available

Case shape

Rectangular7Reviewgadgetsandwearables.com/2025/06/17/amazfit-active-2-square-vs-roundRead 15 October 2026Square body in the comparison table. The schema has no square option, so rectangular

Rectangular7Reviewtechradar.com/reviews/fitbit-versa-4Read 6 October 2026Design and display: a friendly-looking square-faced watch. The Google Store gives equal 40.5 mm length and width.

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.

Mixed materials1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Aluminium1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Materials: The housing and buckle on Versa 4 are made of aluminum.

Case material (as published)

Stainless steel bezel, Fiber-reinforced polymer case1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Technical Specifications, Body Material

Aluminum1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026

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

Not available

Plastic7Reviewtechradar.com/reviews/fitbit-versa-4Read 6 October 2026Design and display: the bezel is aluminum and the rear is plastic. Fitbit publishes no back material.

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

Height43.32Width36.9Thickness9mm(1.7 × 1.5 × 0.4 in)1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Dimensions without heart rate base: 43.32 x 36.9 x 9 mm, read as height x width x thickness

Height40.5Width40.5Thickness11.2mm(1.6 × 1.6 × 0.4 in)2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026Dimensions and weight: Length 40.5 mm, Width 40.5 mm, Height 11.2 mm. Height is stored as thickness. The listed weight of 37.64 g does not say whether it includes the band, so neither weight field is filled.

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

31.4g(1.1 oz)1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Without strap

Not available

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

3 of 8 differ

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

5ATM1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Footnote 4: 5 ATM per ISO 22810:2010, SGS report SHES250300481871. Suitable for splashes, snow, showering or swimming

5ATM1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Environmental conditions: Water resistant up to 50 meters. Fitbit publishes no ATM figure. 50 m equals the 5 ATM static pressure rating.12Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 7 October 2026Maker comparison explicitly publishes 5 ATM for Versa 4. The existing value is now directly maker-supported, without deriving pressure from metres.

Water resistance standard

ISO 22810:20101Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Footnote 4

IEC 605291Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Manual printed page 74 explicitly rates FB523 IPX8 under IEC 60529 up to 50 metres. IEC 60529 applies to water ingress, not an inferred ISO pressure or diving test. Maker comparison independently publishes 5 ATM.

Dust and water rating

Not available

IP6X, IPX81Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026IP Rating section: IPX8 under IEC 60529 up to a depth of 50 meters, and IP6X dust-tight. Stored as the two published codes.

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.

Min0Max45°C4Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/imgs/electronic_manual.pdfRead 15 October 2026Basic Parameters, page 5: 0 to 45 degrees C. Model numbers A2434 and A2440 are printed in the same table

Min-10Max45°C1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Environmental conditions table: operating temperature 14 to 113 F (-10 to 45 C). Non-operating and charging (0 to 35 C) ranges excluded. The Google Store specs page prints -14 to 113 F, which conflicts. The manual table, which states both units, is used.

Display

6 of 14 differ

Display type

OLED1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

OLED2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026

Display type (as published)

AMOLED1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

AMOLED2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026Display: AMOLED display, Corning Gorilla Glass 3.

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

1.75in(4.4 cm)1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

1.58in(4 cm)6Reviewpcmag.com/reviews/fitbit-versa-4Read 6 October 2026Both feature a 1.58-inch AMOLED display (Versa 4 and Sense 2). Fitbit publishes no diagonal. Android Central, Trusted Reviews and Stuff state the same 1.58 inches.

Resolution

390 × 450px1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

336 × 336px6Reviewpcmag.com/reviews/fitbit-versa-4Read 6 October 2026The 336-by-336-pixel display. TechRadar and Android Central state 336 x 336 as well. No pixel density is stored because none is published.7Reviewtechradar.com/reviews/fitbit-versa-4Read 6 October 2026The screen is a 336 x 336 pixel OLED just like the Versa 3's.

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

341ppi1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Not available

Display area

Not available

Not available

Touchscreen

Yes3Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/files/user-manual.pdf.pdfRead 15 October 2026Basic operations, pages 2-3: tap and swipe on the screen

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Navigate Versa 4: Versa 4 has a color AMOLED touchscreen display and 1 button.

Max refresh rateiHighest published display refresh rate in active operation.

Not available

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.

2,000nits1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Footnote 1: 2,000 nits is not supported if battery life is below 30 percent. Depending on the environment the watch can reach up to 2,000 nits with automatic brightness enabled

Not available

Minimum brightness

Not available

Not available

Always-on display

Yes3Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/files/user-manual.pdf.pdfRead 15 October 2026Always On Display section, page 4

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Adjust always-on display section.

Display cover

Sapphire1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Gorilla Glass2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026

Display cover (as published)

Sapphire glass1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Spec row lists a sapphire cover. The page copy names scratch-resistant sapphire glass

Corning Gorilla Glass 32Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026

Platform

6 of 15 differ

Platform

Proprietary8Maker product pagedocs.zepp.com/docs/reference/related-resources/device-listRead 15 October 2026Zepp OS developer documentation lists the watch as a Zepp OS device

Proprietary3Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 6 October 2026

OS at launch

Zepp OS 5.07Reviewgadgetsandwearables.com/2025/06/17/amazfit-active-2-square-vs-roundRead 15 October 2026The Square comes with ZeppOS 5.0 out of the box. One Russian launch article says 4.5, which contradicts this

Fitbit OS3Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 6 October 2026Powered by the new Fitbit OS. No version number is published.

Software

Not available

Not available

Latest OS

Zepp OS 5.08Maker product pagedocs.zepp.com/docs/reference/related-resources/device-listRead 15 October 2026Amazfit Active 2 (Square) row: latest Zepp OS version 5.0. Latest API level 4.2 is separate

Fitbit OS, firmware 220.3113Maker product pagesupport.google.com/googlehealth/answer/14236725Read 7 October 2026Latest maker-listed Versa 4 device firmware on access date. No unreported Fitbit OS major version is assigned. Updates are phased.

Works with

Android, iOS1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

iOS, Android2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026

Phone requirement

Android 7.0 and above, iOS 15.0 and above1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Supported Devices: Android 7.0 and above, iOS 15.0 and above

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_versa_4_specsRead 7 October 2026Requirements section, current on the access date. The 2022 launch requirement may have been lower.

App store

Yes3Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/files/user-manual.pdf.pdfRead 15 October 2026Mini App installation, page 36: download and install more apps in the app store

No6Reviewpcmag.com/reviews/fitbit-versa-4Read 6 October 2026The Versa 4 does not support third-party app downloads, with the exception of watch faces.

Voice assistants

Zepp Flow1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Amazon Alexa1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Voice Assistant: Amazon Alexa Built-in. Needs the phone app running in the background. Not available in all countries.

Chipset

Not available

Not available

Process

Not available

Not available

CPU cores

Not available

Not available

CPU configuration

Not available

Not available

Max CPU clock

Not available

Not available

GPU

Not available

Not available

Low-power coprocessor

Not available

Not available

Memory

None of 2 known

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.

Not available

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.

Not available

Not available

Health sensors

3 of 8 differ

Heart rate sensor

BioTracker 6.0 PPG biosensor (dual LED, 5PD)1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Sensors, Health: BioTracker 6.0 PPG biometric sensor. The launch release names a dual-LED and 5PD build

Multi-path optical heart rate sensor1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Sensors and Components: Multi-path optical heart rate tracker. Google Store spells it Multi-path optical heart rate sensor.

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

No6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026Electrical heart rate row says No and ECG says No

No4Press releaseblog.google/products-and-platforms/devices/fitbit/fitbit-sense-2-versa-4Read 6 October 2026The ECG app is named for Sense 2 only, while Irregular Heart Rhythm Notifications are on both watches. Versa 4 has no electrical heart sensor in its sensor list.6Reviewpcmag.com/reviews/fitbit-versa-4Read 6 October 2026The Sense 2 adds an electrocardiogram (ECG) sensor.

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

Yes1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Sensors and Components: red and infrared sensors for oxygen saturation (SpO2) monitoring. Not available in all countries and not for medical use.

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

Yes1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 202624H Monitoring lists skin temperature (thermometer)

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Track your sleep and Advanced health metrics: skin temperature variation from personal baseline. It reports variation only, not an absolute temperature.2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026Sensors and components: Device temperature sensor (skin temperature variation available in the Google Health app). Variation only, not in all markets.

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

None6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026Blood pressure row says No

None14Spec databasegadgetsandwearables.com/technical-specs/fitbit-versa-4Read 7 October 2026Explicit absence of blood-pressure feature. Maker comparison also lacks blood-pressure trends.

Body composition sensor

No6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026Body composition row says No

Not available

Skin conductance (EDA)

No6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026Galvanic skin response row says No

No3Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 6 October 2026The continuous EDA (cEDA) Body Response sensor is described for Sense 2 only. Versa 4 has no EDA sensor in its own sensor list.6Reviewpcmag.com/reviews/fitbit-versa-4Read 6 October 2026The Sense 2 adds a cEDA sensor and an ECG sensor that the Versa 4 lacks.

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

Not available

Irregular Heart Rhythm Notifications: FDA clearance, Irregular Heart Rhythm Notifications: EU clearance4Press releaseblog.google/products-and-platforms/devices/fitbit/fitbit-sense-2-versa-4Read 6 October 2026Both of these tools have FDA and EU clearance: the Sense 2 ECG app and the Irregular Heart Rhythm Notifications on both watches. Select countries only, not for people under 22 or with known AFib.

Motion and environment sensors

2 of 9 differ

Accelerometer

Yes1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026

Accelerometer range

Not available

Not available

Gyroscope

Yes1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

No12Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 7 October 2026Versa 4 column explicitly lacks the gyroscope.

Barometric altimeter

Yes1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Sensors and Components: Altimeter, which tracks altitude changes. Restart section names a small hole on the device for the altimeter, which is the pressure-sensor vent. Published only as Altimeter.

Compass

Yes3Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/files/user-manual.pdf.pdfRead 15 October 2026Compass app, page 34. The sensor list names a geomagnetic sensor

No12Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 7 October 2026Versa 4 column explicitly lacks the compass.

Ambient light sensor

Yes1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026

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, Blood oxygen app, Heart rate variability, Sleep tracking, Sleep stages, Stress tracking, Readiness score, Cycle tracking1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 202624H heart rate, blood oxygen and stress. Alerts for abnormally high and low heart rate and low blood oxygen. Sleep HRV and sleep stages. Daily readiness score. Menstrual cycle tracking. Not medical devices (footnote 2)

Continuous heart rate, Heart rate alerts, Irregular rhythm notifications, Blood oxygen app, Heart rate variability, Sleep tracking, Sleep stages, Stress tracking, Readiness score, Cycle tracking1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Today app stats: heart rate, oxygen saturation, readiness, stress management score, menstrual health. Track your sleep: sleep stages. Receive heart-rate notifications: high and low heart rate. Advanced health metrics: heart-rate variability. Daily readiness and some detail need Fitbit Premium per the maker blog.3Press releaseblog.google/products-and-platforms/devices/fitbit/versa-4-sense-2Read 6 October 202624/7 heart rate monitoring, sleep tracking and Stress Management Score.4Press releaseblog.google/products-and-platforms/devices/fitbit/fitbit-sense-2-versa-4Read 6 October 2026Irregular Heart Rhythm Notifications on both watches.

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, Training load, Recovery advice, Pool swim, Open water swim, Strength rep counting, Interval workouts, Route navigation, Turn-by-turn navigation, Trackback, Ski resort maps1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Smart recognition of 8 sports movements. Strength training counts reps, sets and rest. Pool and open water swimming modes. Interval training on the watch. Downloadable maps with turn-by-turn directions. Ski resort maps. VO2 max, training load and recovery come from the manual

Automatic workout detection, VO2 max, Pool swim, Interval workouts, Turn-by-turn navigation1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Track your exercise automatically (SmartTrack, 15 minute minimum). Exercise settings list Pool Length and Interval. Google Maps app gives turn-by-turn directions and needs the paired phone nearby with the app running. View your cardio fitness score in the Fitbit app (stored as vo2_max, see the Google Health VO2 max help page).9Maker product pagesupport.google.com/googlehealth/answer/14237924Read 6 October 2026Learn about your VO2 max: tap VO2 max (formerly known as cardio fitness score). The Versa 4 manual names the cardio fitness score. VO2 max is estimated during outdoor runs with GPS.

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.

Heart rate strap, Power meter, Speed and cadence1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Heart rate belt, running and cycling power meter, cycling speedometer and cadence meter. Footnote 17: BLE devices only

Not available

Safety

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

No6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026Navigation, safety and special features row says No

No12Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 7 October 2026Versa 4 column explicitly lacks general fall detection.

Car crash detection

Not available

No12Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 7 October 2026Versa 4 column explicitly lacks car crash detection.

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.

No6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026Emergency SOS row says No

No12Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 7 October 2026Versa 4 column explicitly lacks manual emergency SOS.

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.

No6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026LED flashlight row says No. The manual Control Center lists a Flashlight control that lights the screen

No14Spec databasegadgetsandwearables.com/technical-specs/fitbit-versa-4Read 7 October 2026Explicit absence of dedicated LED flashlight. Display illumination is not that hardware feature.

Positioning

2 of 3 differ

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

GPS, GLONASS, Galileo, BeiDou, QZSS6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026GNSS rows list GPS, Galileo, GLONASS, QZSS and BeiDou. This matches the maker's five satellite systems

GPS, GLONASS1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 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.

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

Not available

Not available

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

Yes1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Free downloadable maps from the Zepp App with turn-by-turn directions. Footnote 5: OSM map files imported to the watch

No14Spec databasegadgetsandwearables.com/technical-specs/fitbit-versa-4Read 7 October 2026Explicit no offline maps. Maker manual requires phone navigation and background app. Directions are not stored cartographic maps.

Connectivity

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

Yes1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

Not available

Bluetooth version

5.21Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Connection: Bluetooth 5.2, BLE

5.01Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Wireless technology: Bluetooth 5.0 radio transceiver and NFC chip. Wi-Fi hardware is listed as deactivated and cannot be turned on, so no Wi-Fi standard is stored.

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

Not available

Not available

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.

No6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026Cellular row says No

No8Reviewtomsguide.com/reviews/fitbit-versa-4Read 7 October 2026Fitbit's watches don't have cellular support. Only one radio configuration (FB523, Bluetooth and NFC) exists in the manual.

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.

Yes2Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026Zepp Pay Contactless Payment section: NFC technology. The US page names Zepp Pay NFC only in the battery test scenario

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026

Contactless payments

Yes2Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026Zepp Pay binds up to eight bank cards. Footnote 14: supported by Curve and participating issuer banks in 31 European countries. Only usable for payments in Europe

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026

Payment services

Zepp Pay2Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026Zepp Pay, in Europe through Curve

Google Wallet1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Contactless Payments: set up Google Wallet in the app. The manual also names the legacy Fitbit Pay app, which Google is phasing out. Card, bank and country limits apply.

Ultra-wideband

No6Spec databasegadgetsandwearables.com/technical-specs/amazfit-active-2-squareRead 15 October 2026UWB row says No

No12Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 7 October 2026Versa 4 column explicitly lacks UWB radio.

Satellite

Not available

None12Maker product pagestore.google.com/gb/magazine/google_pixel_watch_compareRead 7 October 2026No satellite SOS. Published transmitters are Bluetooth/NFC. GPS reception is separate.

ANT+

No1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Footnote 17: connection to peripheral devices only supports BLE devices

Not available

Audio

0 of 4 differ

Speaker

Yes1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Spec table: Mic and Speaker: Support

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 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.

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 only1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026FAQ: Bluetooth phone calls through the paired phone. No cellular model

Phone only1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Answer or reject phone calls: on-wrist calls through the paired iPhone or Android phone, which must be nearby with the Fitbit app running. No cellular model exists.

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

No7Reviewgadgetsandwearables.com/2025/06/17/amazfit-active-2-square-vs-roundRead 15 October 2026Comparison table: Music storage No for the Square. The full manual only has phone music controls

No7Reviewtechradar.com/reviews/fitbit-versa-4Read 6 October 2026You can't store music on the watch. Tom's Guide also says you can't download music to the Versa 4.8Reviewtomsguide.com/reviews/fitbit-versa-4Read 7 October 2026You can't download music to the Versa 4 or install third-party apps.

Controls

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

24Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/imgs/electronic_manual.pdfRead 15 October 2026About the Watch, page 1 shows two buttons. The maker spec table lists Buttons: 2

11Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Navigate Versa 4: color AMOLED touchscreen display and 1 button.

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

Upper button, Lower button4Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/imgs/electronic_manual.pdfRead 15 October 2026About the Watch, page 1: an upper and a lower button

Button1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Maker calls the single operating control Button. Strap-release latches are excluded.

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

None4Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/imgs/electronic_manual.pdfRead 15 October 2026No crown is shown or described. The watch has two buttons and a touchscreen

None1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026The controls are the touchscreen and 1 button. There is no rotating crown.

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

Not available

Not available

Gestures

Cover the screen to turn it off3Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/files/user-manual.pdf.pdfRead 15 October 2026Common gesture operations, page 3: cover the screen to turn it off

Turn your wrist, Briefly cover the watch face with your opposite hand, Triple-tap the screen1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Manual screen-wake setting documents selectable wrist-turn wake. Printed page 22 says briefly covering the face turns the screen off, except when always-on display is enabled. Printed page 20 says triple-tap zoom works after Magnify is enabled. These are interface gestures, not unsupported inertial sensor features.

Battery and charging

8 of 13 differ

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

260mAh1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026260 mAh (rated value)

Not available

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.

AAmazfit Active 2 (Square)

Mode	With solar	Hours (h)
Smartwatch	No	240
Low power	No	456
Heavy use	No	120
GPS	No	21

Source1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Typical use 10 days (240 h), battery saver 19 days (456 h), heavy use 5 days (120 h), continuous GPS 21 h. Footnote 8: typical use is HR every 10 minutes, sleep monitoring, five daily SpO2 readings, 150 notifications a day and three 30-minute GPS workouts a week. Heavy use is HR every minute with stress and sleep-breathing monitoring and longer screen use. Battery saver turns off health monitoring and GPS. The maker does not state the GPS mode or satellite systems for the 21 h figure

BFitbit Versa 4

Mode	With solar	Hours (h)
Smartwatch	No	144
Always-on	No	72
GPS	No	12

Source5Maker product pagesupport.google.com/googlehealth/answer/14226518Read 6 October 2026Battery life table: Fitbit Versa 4* 6+ days, stored as 144 h as a minimum figure. Footnote *: always-on display and GPS need more frequent charging. If you turn on always-on display: Versa 4 up to 3 days (72 h). If you use built-in GPS continuously: Versa 4 up to 12 hours. The 2025 pre-production test footnote (**) belongs to Google Fitbit Air, not Versa 4.

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.

240h=CalculatedFrom Claimed battery life

144h=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.

Not available

72h=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.

21h=CalculatedFrom Claimed battery life

12h=CalculatedFrom Claimed battery life

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 pins4Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/imgs/electronic_manual.pdfRead 15 October 2026Charging the Watch, page 3: metal contacts on the back of the watch meet the charging base. USB-C attaches to the base

Magnetic pins1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Charge your watch: the cable end attaches magnetically to the port on the back and its pins align with the port.

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

Charges on the supplied magnetic charging base. A USB-C cable is not included. The manual recommends a power adapter with a charging current of 1 A or above.4Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/imgs/electronic_manual.pdfRead 15 October 2026Charging the Watch, page 3: use the supplied base and a power adapter with a charging current of 1 A or above

Not available

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.

Not available

Yes4Press releaseblog.google/products-and-platforms/devices/fitbit/fitbit-sense-2-versa-4Read 6 October 2026Fast charging gets you a full day's worth of battery in just 12 minutes.

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

Not available

Charge time12 minUse time24 h1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Charge Versa 4 for 12 minutes for 24 hours of battery life.

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.

120min1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Theoretical charging duration approx. 2 hours. The FAQ says about 2 hours from empty. Maker claim, no adapter named

120min2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026Battery and power: Charge time (0-100%): Two hours. The manual says charging fully takes about 1-2 hours.

Measured

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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.

Not available

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.

Not available

Not available

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.

Not available

60min8Reviewtomsguide.com/reviews/fitbit-versa-4Read 7 October 2026Reviewer observed depleted-to-full charging using the proprietary USB-A-ended charging arrangement. Standard 40.5 mm Copper Rose review unit. USB power adapter, ambient temperature and firmware are unstated. This is a measured result, separate from the maker two-hour claim. Partial-discharge runtime projections are not added.

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.

20mm1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Strap Width: 20mm

Not available

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

Yes2Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026Strap, Materials: Leather, Quick release

Yes1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Change the band: slide the flat latch button toward the band and pull. Attach by pressing until it clicks. No tools.

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

20 mm quick release2Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026Strap, Width: 20mm, Materials: Leather, Quick release. The silicone strap range is also 20 mm

Proprietary latch connector. Fitbit Sense, Sense 2 and Versa 3 bands are compatible.1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Change the band: Fitbit Sense, Fitbit Sense 2, and Fitbit Versa 3 bands are compatible with Versa 4. Turn over Versa 4 and find the band latches. Slide the flat button toward the band to release the latch. Proprietary connector, no lug width published.

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

Leather1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Standard strap is leather. The US package adds a red sport silicone strap

Other1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Supplied classic band is elastomer. Other preserves that wording without guessing silicone, HNBR or fluoroelastomer.

Strap

Not available

Classic band2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026Maker box lists Classic band in small and large sizes. Manual printed page 57 states flexible durable elastomer. band_material=other preserves that published material without guessing a specific polymer.

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

AAmazfit Active 2 (Square)

Size	Wrist (min) (mm)	Wrist (max) (mm)
Leather strap	150	210
Silicone strap	135	195

Source1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Min. and Max. Wrist Dimensions: leather 150-210 mm, silicone 135-195 mm

BFitbit Versa 4

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

Source1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Band size table: Small 140-180 mm, Large 180-220 mm wrist circumference. The Google Store specs page prints Small 5.1-7 in and Large 6.5-8.6 in. The manual table is used.

Regulatory

1 of 3 differ

FCC ID

Not available

XRAFB5231Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026USA FCC statement: Model FB523, FCC ID XRAFB523. IC 8542A-FB523.

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

Not available

RED (2014/53/EU), UK Radio Equipment Regulations 2017, IEC 62368-1:20181Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Manual printed page 62 declares FB523 compliance with RED 2014/53/EU. Printed page 72 declares UK Radio Equipment Regulations 2017. Printed page 74 lists testing to IEC 62368-1:2018 safety certification. These are model declarations and safety tests, not medical, military or diving certifications.

In the box

1 of 2 differ

In the box

Smartwatch (including standard strap and additional red sport silicone strap), Magnetic charging base (no USB Type-C cable), Instruction manual1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Packing list, US package2Maker product pageeu.amazfit.com/products/active-2-squareRead 15 October 2026EU packing list lists the standard strap only

Fitbit Versa 4, Classic band (small & large), Charging cable2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026

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

No1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026Magnetic charging base without USB-C cable

No2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026What's in the box lists only Fitbit Versa 4, Classic band (small & large) and Charging cable. No power adapter.

Links

Not compared

Product page

us.amazfit.com/products/active-2-square1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

store.google.com/us/product/fitbit_versa_4_specs2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026

Spec sheet

us.amazfit.com/products/active-2-square1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 2026

store.google.com/us/product/fitbit_versa_4_specs2Maker product pagestore.google.com/us/product/fitbit_versa_4_specsRead 7 October 2026Online maker specification sheet for regulatory model FB523.

Manual

support.amazfit.com/en/amazfit_active_2%28square%29/files/user-manual.pdf.pdf3Owner's manualsupport.amazfit.com/en/amazfit_active_2%28square%29/files/user-manual.pdf.pdfRead 15 October 2026Active 2 (Square) user manual, 37 pages, June 2025

storage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsK1Owner's manualstorage.googleapis.com/support-kms-prod/aMr9HIIq7XWrbNCLHQyr9sA3nP2Y6JUWITsKRead 7 October 2026Versa 4 User Manual Version 2.1, linked from the Fitbit user manuals help page (support.google.com/googlehealth/answer/14253977).

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.

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Warranty

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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.

1year1Maker product pageus.amazfit.com/products/active-2-squareRead 15 October 20261 year warranty, US store

1year15Maker product pagesupport.google.com/product-documentation/answer/14815834Read 7 October 2026Manufacturer contractual warranty for original new US Fitbit Versa 4 / FB523 retail units purchased before July 11, 2023: one year. Exact US Abt FB523BKBK-US also states one-year limited parts/labour warranty. The original maker contract separately gives two years for an EEA resident purchasing in the EEA, including the retained Estonian market. This scalar applies only to the stated US source-market contract, not all variants. Later purchases use the separate Google Hardware Warranty Center terms.16Retailer pageabt.com/Fitbit-Versa-4-Graphite-Aluminum-Black-Strap-Fitness-Smartwatch-24mm-FB523BKBKUS/p/182318.htmlRead 7 October 2026Exact new US FB523BKBK-US listing states one-year limited parts and labour warranty. This source-market claim is distinct from the maker two-year EEA contract and does not set the Estonian variant warranty.

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