Samsung released Galaxy Fit3 firmware R390XXU0AZA3 on March 5, 2026. Reports place the rollout across multiple regions, including North America, but “worldwide” does not mean every US band received it at the same time. Check the connected Fit3 in Galaxy Wearable to see whether your device is eligible.
Samsung’s official notice describes this as a stability and reliability update for the Fit3 (SM-R390) running RTOS 1.0. It does not document a new fitness feature, a major interface redesign, or a move to Wear OS.
What the Galaxy Fit3 update is
| Item | Details |
|---|---|
| Device | Samsung Galaxy Fit3, model SM-R390 |
| Firmware | R390XXU0AZA3 |
| Samsung release date | March 5, 2026; regional availability may follow later |
| Platform | RTOS 1.0 |
| Official changelog | Stability and reliability improvements; improved device behavior |
| Reported download size | Approximately 17.42 MB, according to secondary coverage; package size can vary by region |
Samsung’s firmware page gives no itemized list of bugs or affected functions. A separate report says the package includes the January 2026 security patch, but Samsung’s English notification page does not clearly show a separate security-patch field, so that detail should be treated as secondary-source information.
Samsung’s official changelog is available at Samsung’s Galaxy Fit3 firmware page.
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![SAMSUNG Galaxy FIT 3 [2024] 1.6' AMOLED Display | 14 Days Battery Life | 100+ Watchfaces | 100+ Exercise Modes | International Model - (Gray)](https://m.media-amazon.com/images/I/31JyN7HkB8L._SL160_.jpg)
- Vibrant 1.6” AMOLED Display – Large, high-res screen with smooth touch for easy navigation
- 5ATM & IP68 Water Resistance – Swim-ready and dust-resistant for active lifestyles
- Up to 14 Days Battery Life – Powerful 208mAh battery for long-lasting performance
- 101+ Workout Modes with Auto Detection – Automatically tracks common workouts for seamless fitness tracking. Advanced Health Tracking – Includes sleep coaching, SpO2, heart rate, and snore detection
- International Model No Warranty in the US. ONLY compatible with Android devices. Samsung Pay - Not Supported. NOT compatible with iPhone or iOS devices.
Does “worldwide” include the United States?
Secondary reporting says Samsung first released R390XXU0AZA3 in South Korea and then expanded it across Africa, Asia, Australia, Europe, Latin America and North America. That supports calling it an international or global rollout.
It does not establish a single US release date or prove that every US Galaxy Fit3 has the update. Samsung says update availability and changes can vary by country, model and operator environment. A US owner’s practical answer is therefore the result shown for their own connected band in Galaxy Wearable.
See the rollout report at SamMobile.
What Samsung says it improves
The confirmed benefits are limited to stability, reliability and generally improved device behavior. Samsung does not promise longer battery life, more accurate sleep or workout tracking, better weather synchronization, fewer notification failures or a fix for Bluetooth disconnects.
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![SAMSUNG Galaxy FIT 3 [2025, 40MM] 1.6' AMOLED Display | IP68 Water Resistant | 14 Days Battery Life | 100+ Watchfaces | 100+ Exercise Modes | International Model (Fast Charger Bundle, Black)](https://m.media-amazon.com/images/I/418RlYE+wfL._SL160_.jpg)
- Vibrant 1.6” AMOLED Display – Large, high-res screen with smooth touch for easy navigation
- 5ATM & IP68 Water Resistance – Swim-ready and dust-resistant for active lifestyles
- Up to 14 Days Battery Life – Powerful 208mAh battery for long-lasting performance
- 101+ Workout Modes with Auto Detection – Automatically tracks common workouts for seamless fitness tracking. Advanced Health Tracking – Includes sleep coaching, SpO2, heart rate, and snore detection
- International Model No Warranty in the US. ONLY compatible with Android devices. Samsung Pay - Not Supported. NOT compatible with iPhone or iOS devices.
Maintenance firmware can improve background operation without producing a visible change on the band. If you install it and see the same tiles and menus, that is consistent with the published changelog.
How US owners install it
Use the Galaxy Wearable phone app, not the standard Galaxy Watch update procedure. Samsung’s US support guidance specifically warns that its normal Watch instructions do not apply to Galaxy Fit devices. Menu names can differ by Galaxy Wearable version and phone model, but the process is generally:
- Charge the Fit3 sufficiently before starting.
- Keep the band close to its paired Android phone, with Bluetooth enabled and the connection active.
- Open Galaxy Wearable and select the connected Galaxy Fit3.
- Open the band’s settings or software-update area.
- Choose Band software update or Download and install, depending on the app version.
- Follow the on-screen prompts. Keep the phone and band nearby and do not interrupt the transfer.
- Let the Fit3 restart, then wait for Galaxy Wearable to reconnect.
Samsung’s US guidance is at Samsung Support. It is general wearable guidance, so use the Fit3-specific controls shown by your app.
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![SAMSUNG Galaxy FIT 3 [2024] 1.6' AMOLED Display | 14 Days Battery Life | 100+ Watchfaces | 100+ Exercise Modes | International Model - (Pink)](https://m.media-amazon.com/images/I/31mWI71wuzL._SL160_.jpg)
- Vibrant 1.6” AMOLED Display – Large, high-res screen with smooth touch for easy navigation
- 5ATM & IP68 Water Resistance – Swim-ready and dust-resistant for active lifestyles
- Up to 14 Days Battery Life – Powerful 208mAh battery for long-lasting performance
- 101+ Workout Modes with Auto Detection – Automatically tracks common workouts for seamless fitness tracking. Advanced Health Tracking – Includes sleep coaching, SpO2, heart rate, and snore detection
- International Model No Warranty in the US. ONLY compatible with Android devices. Samsung Pay - Not Supported. NOT compatible with iPhone or iOS devices.
If R390XXU0AZA3 does not appear
A missing update does not necessarily mean the rollout report is wrong. Staged distribution, a different regional product code, an inactive Bluetooth connection or an outdated companion app can all affect discovery.
- Reconnect the Fit3 in Galaxy Wearable and check again later.
- Update Galaxy Wearable and the Galaxy Fit3 Plugin from the relevant app store.
- Restart both the phone and the band before checking again.
- Make sure the phone has adequate battery and storage and that the Bluetooth link is stable.
- Confirm that the app is checking the connected Fit3 rather than another wearable.
Do not use unofficial firmware files, VPN or region spoofing, or sideloading as a normal workaround. Samsung does not establish those methods as supported, and a factory reset is not documented as a requirement for this update.
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How to verify the installed build
In Galaxy Wearable, open the connected Fit3’s software-information or update screen and compare the displayed firmware with R390XXU0AZA3. The exact menu location varies by app release, so follow the labels on your phone rather than relying on a Galaxy Watch tutorial.
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- Only compatible with Samsung Galaxy Fit 3 SM-R390 [2024]
- Offering full protection for your watch against Scratches, drops, and bumps
- Made of high-quality PC materials, and will not add extra bulk to your watch
- 1.Clearning the Smartwatch 2.Peel off the Smartwatch sticker and install from Smartwatch crown side 3.Press the frame and install it completely
- This product includes a protective case. Please note that the device and watch band are not included
Also distinguish the four separate software layers you may see in the app ecosystem:
- Galaxy Fit3 firmware: the software installed on the band.
- Galaxy Wearable: Samsung’s phone companion app.
- Galaxy Fit3 Plugin: the component that synchronizes the band with Galaxy Wearable.
- Samsung Health: the health-data app that receives synced information.
The Galaxy Fit3 Plugin listing on Google Play says the plugin synchronizes the band and requires Galaxy Wearable; updating the plugin alone does not prove that Fit3 firmware has been installed.
What this update does not add
Samsung’s March 5 changelog lists no new fitness modes, tiles, health measurements or interface features. The earlier documented feature addition was a battery tile in firmware R390XXU0AXHD, released September 9, 2024. The previous listed Fit3 firmware, R390XXU0AYB3, dated April 14, 2025, was also described as a stability improvement.
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R390XXU0AZA3 does not change the platform from RTOS 1.0 to Wear OS or Android. It does not add third-party app installation or turn the Fit3 into a Galaxy Watch. Readers seeking a full smartwatch platform should evaluate a Galaxy Watch separately; this firmware is maintenance rather than an upgrade in product category.
Should you install it?
Yes, if Galaxy Wearable offers R390XXU0AZA3 for your band. The official description indicates routine stability and reliability work, and installation is the supported way to receive it. Keep expectations realistic: there may be no visible feature change and Samsung has not tied the package to any specific battery, tracking or connectivity fix.
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