Smartwatches / Compare

Amazfit Active 2 (Square) vs Xiaomi Watch S4

A

Product A: Amazfit

Active 2 (Square)

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B

Product B: Xiaomi

Watch S4

83 of 150 known

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All 150 fields

Every value links to where we found it.

Only differences

AAmazfit Active 2 (Square)

BXiaomi Watch S4

General

7 of 10 differ

Series

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

Watch S3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q4 compares the Watch S4 with its predecessor, the Xiaomi Watch S3, in the same Watch S line.

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

M2425W1, BHR9195GL, BHR9197GL, BHR9199GL4Maker spec sheet (PDF)i02.appmifile.com/229_operatorx_operatorx_xm/29/08/2026/0506b1d933bea38854867532d7b1e253.pdfRead 15 October 2026EU Declaration of Conformity for radio equipment model M2425W1, Smart Watch, listed on Xiaomi's declaration page as Xiaomi Watch S4. The 41 mm Watch S4 is M2502W1 and is a separate product. The standards list covers Bluetooth, NFC and GNSS and has no cellular standard.6Maker product pagemi.com/global/service/support/declaration.htmlRead 15 October 2026Declaration page lists Xiaomi Watch S4 M2425W1 with EU DoC and PSTI documents, separate from Watch S4 41mm M2502W1.7Spec databasegsmarena.com/xiaomi_watch_s4-13476.phpRead 15 October 2026Spec page lists models M2424W1 and M2425W1. Only M2425W1 is documented for the global model, so M2424W1 is not stored.11Retailer pageeuronics.ee/en/phones/watches/smart-watches/bhr9195gl/xiaomi-watch-s4-black-smart-watchRead 15 October 2026Retailer product code BHR9195GL for the black Xiaomi Watch S4, 44.5 g, 486 mAh, Bluetooth 5.3, 4G No.13Retailer pagepood.datafox.ee/xiaomi-watch-s4-rainbow-smart-watchRead 15 October 2026Rainbow product code BHR9199GL.14Retailer pageachatmoinscher.com/comparateur-de-prix-Montre-connectee-sportive/montre-intelligente-xiaomi-s4-bhr9197gl-gris-argente-6941812707432.htmlRead 15 October 2026Silver product code BHR9197GL.

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

6941812732403, 6941812707432, 694181271166812Retailer pagepood.datafox.ee/xiaomi-s4-smartwatch-blackRead 15 October 2026Black BHR9195GL, EAN 6941812732403.13Retailer pagepood.datafox.ee/xiaomi-watch-s4-rainbow-smart-watchRead 15 October 2026Rainbow BHR9199GL, EAN 6941812711668.14Retailer pageachatmoinscher.com/comparateur-de-prix-Montre-connectee-sportive/montre-intelligente-xiaomi-s4-bhr9197gl-gris-argente-6941812707432.htmlRead 15 October 2026Silver BHR9197GL, EAN 6941812707432.

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

29 October 20247Spec databasegsmarena.com/xiaomi_watch_s4-13476.phpRead 15 October 2026Spec page: announced and released 29 October 2024 in China. The global model followed in March 2025.

Status

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

Available2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026The global product page is live with specs and a buy link. GSMArena lists it as available.

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

Xiaomi Watch S5 46mm15Reviewgsmarena.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.

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

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.

€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

€159.9910Press articlefonearena.com/blog/447624/xiaomi-buds-5-pro-watch-s4-electric-scooter-5-max-price-global.htmlRead 15 October 2026Price 159.99 euros for the Watch S4. The article lists no colours and gives no tax treatment. Retail listings put the Rainbow edition at 169.99 euros, which is not a launch price and is not stored.

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

EU10Press articlefonearena.com/blog/447624/xiaomi-buds-5-pro-watch-s4-electric-scooter-5-max-price-global.htmlRead 15 October 2026Euro price from European announcement coverage. The global launch was at MWC 2025.

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, Silver, Rainbow1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Silver, Rainbow and Black.

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 pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026The page sits under Wearables as the Xiaomi Watch S4 smartwatch with a rotating crown and 150+ sports modes.

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

2 March 20275Maker spec sheet (PDF)i02.appmifile.com/791_operatorx_operatorx_xm/05/03/2026/e12c7be544083cc45f26f933fa49ae28.pdfRead 15 October 2026UK PSTI statement for M2425W1 dated 2025/2/6: the defined support period is until 3/2/2027. Xiaomi's other PSTI statements use month/day/year, such as 11/15/2026 and 2/27/2028, so this reads as 2 March 2027. 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.

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

47.3mm1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026The maker states 47.3 mm x 47.3 mm x 12.0 mm. The separate 41 mm Watch S4 has its own page and is not included.

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

Round3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2: round AMOLED display and 47.3 mm diameter.

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

Aluminium1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Aluminum alloy frame. The bezel is stainless steel according to the support FAQ.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2: middle frame entirely aluminium alloy, bezel stainless steel.

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

Aluminium alloy middle frame with PVD coating and stainless steel bezel3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2 and the S3 comparison: aluminium alloy with PVD coating, stainless steel bezel.

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.

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

Height47.3Width47.3Thickness12mm(1.9 × 1.9 × 0.5 in)1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 202647.3 x 47.3 x 12.0 mm. The maker excludes the strap and protrusions. The FAQ gives 14.13 mm thickness with the heart rate bump.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2: diameter 47.3 mm, thickness 12 mm excluding the deco and heart rate sensor.

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

44.5g(1.6 oz)1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 202644.5 g approx., without the in-box strap.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2: 44.5 +/- 1 g, excluding the strap.

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.

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

5ATM1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 20265 ATM, described as 50 m static pressure. The maker says it is not suitable for hot showers, saunas or diving.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q9: 5 ATM, equivalent to 50 m, for pool and shallow-water use and not for diving.

Water resistance standard

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

Not available

Dust and water rating

Not available

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.

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°C9Retailer pageteamplush.by/enRead 15 October 2026Same reseller copy of the manual: working temperature -10 to 45 C.

Display

7 of 14 differ

Display type

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

OLED1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Spec row: 1.43-inch AMOLED display. No LTPO is stated.

Display type (as published)

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

AMOLED1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Spec row: AMOLED display.

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

1.43in(3.6 cm)1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 20261.43-inch AMOLED display, 466 x 466 pixels.

Resolution

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

466 × 466px1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026

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

326ppi1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Published PPI 326.

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026

Max refresh rateiHighest published display refresh rate in active operation.

Not available

60Hz1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 202660 Hz refresh rate. The maker notes it may vary across interfaces.

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

2,200nits1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Peak 2200 nits is when only part of the screen lights up. HBM 1500 nits is the full-screen maximum. No reviewer measurement is substituted.

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

Yes2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026Support FAQ has the AOD controls. The overview page announces colour always-on displays.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q26: Always-on display supported, with Smart or Scheduled modes.

Display cover

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

Other glass3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2: Panda Glass cover. It is not a named Gorilla Glass or sapphire.

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

Panda Glass3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2: Panda Glass.

Platform

5 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

Proprietary1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Operating system: Xiaomi HyperOS 2, Xiaomi's own software. No Wear OS or other third-party watch platform is named.

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

Xiaomi HyperOS 21Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026

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

Not available

Works with

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

Android, iOS1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Supports Android 8.0 and above, or iOS 14.0 and above.

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

Android 8.0 or later, or iOS 14.0 or later, with the Mi Fitness app1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026The Mi Fitness app is required for pairing according to the support FAQ.

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

Not available

Voice assistants

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

Not available

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

6 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

Heart rate sensor (with blood oxygen sensor)1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Sensors row: heart rate sensor (with blood oxygen sensor). No sensor generation is named.

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

Not available

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026

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)

Not available

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

Not available

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

Not available

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

Not available

Not available

Motion and environment sensors

0 of 9 differ

Accelerometer

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026

Accelerometer range

Not available

Not available

Gyroscope

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026

Barometric altimeter

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Sensors row lists an electronic compass.

Ambient light sensor

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 20263Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Brightness Auto adjusts to ambient light.

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, Blood oxygen app, Sleep tracking, Sleep stages, Stress tracking, Cycle tracking2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026Overview: heart rate, stress, blood oxygen and sleep monitoring, all-day options that need to be switched on. These are not medical features.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Health pages: all-day heart rate, blood oxygen and stress, sleep stages (deep, light, REM, awake) and the Cycles app.

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, Training load, Running dynamics, Pool swim, Open water swim2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026Overview: running form recognition (vertical ratio, vertical amplitude, ground contact time) and 150+ sports modes.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Workout Q1: auto detect for walking, running, cycling, rower, elliptical and jump rope. Q2 workout data: vertical stride ratio, vertical amplitude and ground contact time in running. 17 modes give pro data including pool and open water swimming. The Training State app manages training load.11Retailer pageeuronics.ee/en/phones/watches/smart-watches/bhr9195gl/xiaomi-watch-s4-black-smart-watchRead 15 October 2026Retailer spec tab lists maximal oxygen uptake (VO2 max) measurements as Yes.

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

3 of 6 differ

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

Not available

Car crash detection

Not available

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.

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

Not available

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

Not available

Positioning

3 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 (L1 + L5), Galileo (E1 + E5a), GLONASS (G1), BeiDou (B1I + B1C + B2a), QZSS (L1 + L5)1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Satellite systems: GPS, Galileo, Glonass, BeiDou and QZSS. The overview page says L1+L5 dual-frequency GNSS. The per-constellation bands come from the reseller copy of the manual regulatory table.7Spec databasegsmarena.com/xiaomi_watch_s4-13476.phpRead 15 October 2026Positioning: GPS (L1+L5), GLONASS, GALILEO, BDS, QZSS.9Retailer pageteamplush.by/enRead 15 October 2026Reseller page reproducing the M2425W1 manual regulatory table: GPS L1 / Galileo E1 / GLONASS G1 / BDS B1I, B1C / QZSS L1 at 1559-1610 MHz, and GPS L5 / Galileo E5a / BDS B2A / QZSS L5 at 1164-1215 MHz. This agrees with the maker's L1+L5 claim and GSMArena. Xiaomi's own manual PDF was not found, so the reseller copy is the source.

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-s4Read 15 October 2026Overview: L1+L5 dual-frequency GNSS of five satellite positioning systems from an independent chip.

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

Not available

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026

Bluetooth version

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

5.31Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Wireless connectivity: Bluetooth 5.3.7Spec databasegsmarena.com/xiaomi_watch_s4-13476.phpRead 15 October 2026Bluetooth 5.3, A2DP, LE.9Retailer pageteamplush.by/enRead 15 October 2026The copied table lists Bluetooth 5.3 at 2400-2483.5 MHz.

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

No7Spec databasegsmarena.com/xiaomi_watch_s4-13476.phpRead 15 October 2026WLAN: No.9Retailer pageteamplush.by/enRead 15 October 2026The copied radio table lists only GNSS, Bluetooth and NFC, with no Wi-Fi radio.

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

No7Spec databasegsmarena.com/xiaomi_watch_s4-13476.phpRead 15 October 2026Versions: eSIM and NFC (China), Bluetooth and NFC (China), Bluetooth only (International). The global page and the EU declaration list no cellular radio, so the global model has no 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.

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026NFC: Supported. The maker says availability may vary by region.9Retailer pageteamplush.by/enRead 15 October 2026The copied regulatory table lists an NFC operating frequency of 13.56 MHz.

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

Yes2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026NFC payment supports Mastercard and Visa terminals. Availability varies by region and issuing bank.

Payment services

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

Xiaomi Pay3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026NFC related: bank cards are added through Mi Fitness, Device, Apps, Xiaomi Pay.

Ultra-wideband

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

Not available

Satellite

Not available

Not available

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

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Speaker

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

Yes1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026

Microphones

Not available

21Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Spec row: 2 mics.

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 only1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Bluetooth calling: Supported while the watch stays connected to the phone's Bluetooth. Voice calls from third-party apps are not supported.

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

Yes3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q28: local music playback on the watch. An Android phone downloads the music. An iPhone cannot download songs, but songs already on the watch play.

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

13Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2: the 2 o'clock position has the function button and rotating crown. The 4 o'clock position has the power button. The crown is counted only in Crown.

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

Power button (4 o'clock)3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2: 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.

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

Rotating2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026The overview describes a classic rotating crown.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q2: stainless steel rotating crown that also works as a function button.

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

Not available

None3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q11: the bezel is a removable decorative part that twists on for installation. The maker describes no bezel input.

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

Raise to wake, Double-tap to wake, Wrist flip, Wrist shake, Finger snap, Fist clench2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026Quick gestures and a classic rotating crown are listed. The support FAQ names the gestures.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q24 lists wrist flip, wrist shake, finger snap and fist. Fist works only with HyperOS 2 phones. Raise to wake and double-tap to wake are in the display settings.

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.

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

486mAh1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Capacity 486 mAh. 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.

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

BXiaomi Watch S4

Mode	With solar	Hours (h)
Smartwatch	No	360
Always-on	No	120

Source2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026Up to 15 days typical usage, tested by Xiaomi Internal Labs with factory defaults, AOD off, 100 messages a day, 200 wrist raises a day, 90 minutes of GNSS sports a week and 10-minute heart rate checks. The FAQ gives 14.5 days with an iPhone and 5 days with the Smart AOD option on. Days are converted exactly to hours.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Charging and Battery Q1: typical 15 days (14.5 with an iPhone) and AOD 5 days, with the stated test conditions.

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

360h=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

120h=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

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 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 pins1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 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.

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

2-pin magnetic charging dock with a USB-A cable. The FAQ asks for a USB-A charger with 5 V output and at least 0.5 A.1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026The support FAQ gives the supply requirement.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Charging Q2: USB-A charger with 5 V and at least 0.5 A output.

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

Yes2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026Overview headline: 5 minutes of fast charging delivers 2 days of usage.

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 time5 minUse time48 h2Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 20265 minutes of charging for 2 days of usage. The FAQ says this follows the typical battery model, which is the typical-use workload.3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Charging Q1: 5 minutes of charging provides a 2-day boost under the typical battery model.

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

60min3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Charging Q1 and Q2: about 60 minutes to fully charge.

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.

AAmazfit Active 2 (Square)

Not available

BXiaomi Watch S4

Test	Hours (h)
Mixed use, always-on	48

Source8Reviewgsmarena.com/xiaomi_watch_s4_review-news-67715.phpRead 15 October 2026Reviewer used AOD, notifications, a one-hour daily workout and sleep tracking. The most was three days when the watch nearly died, and two days was a consistent result. Stored as about 48 hours. Firmware and display brightness are not stated.

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

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.

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

22mm3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q7: strap width 22 mm.

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

Yes3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q6: the watch supports quick-release straps released through the spring bar.

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

22 mm quick-release straps with spring bars3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Q6 and Q7: quick-release spring-bar straps, any 22 mm strap.

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

Fluoroelastomer3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Spec page names fluororubber straps for Black and Silver. Fluororubber is stored as fluoroelastomer.

Strap

Not available

Fluororubber strap3Maker product pagemi.com/global/support/faq/details/KA-517264Read 15 October 2026Spec page strap rows for Black and Silver.

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

BXiaomi Watch S4

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

Source1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026The Black and Silver fluororubber straps have an adjustable length of 140-210 mm approx. The maker publishes strap length, stored as the wrist range. The Rainbow set with fluororubber and nylon straps is 135-210 mm.

Regulatory

2 of 3 differ

FCC ID

Not available

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

0.232W/kg9Retailer pageteamplush.by/enRead 15 October 2026Same reseller copy: maximum SAR on the wrist 0.232 W/kg with no gap, against a 4.0 W/kg wrist limit averaged over 10 g, under the EU declaration. The near-mouth value of 0.132 W/kg is a body value and is not stored.

Other certifications

Not available

EU RED 2014/53/EU conformity, RoHS 2011/65/EU conformity4Maker spec sheet (PDF)i02.appmifile.com/229_operatorx_operatorx_xm/29/08/2026/0506b1d933bea38854867532d7b1e253.pdfRead 15 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

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

Xiaomi Watch S4 (including bezel and strap), Magnetic charging dock, User manual (including warranty notice)1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Package contents row.

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

No1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Package contents list only the watch, magnetic charging dock and manual. 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

www.mi.com/global/product/xiaomi-watch-s42Maker product pagemi.com/global/product/xiaomi-watch-s4Read 15 October 2026

Spec sheet

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

www.mi.com/global/product/xiaomi-watch-s4/specs1Maker product pagemi.com/global/product/xiaomi-watch-s4/specsRead 15 October 2026Global specs page. Base case and strap describe the Black version.

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

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.

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

Not available

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