Zepp OS 6: Amazfit Multi-Device Sync and iOS Notifications Explained

Zepp OS 6 just dropped two features that put Amazfit back in the conversation for serious athletes: Multi-Device Activity Sync on the Balance 3 and Balance Ultra, and a confirmed June 2026 timeline for iOS Notification Forwarding in the EU. Both updates are meaningful. Neither is flawless. But together they close real gaps that have kept Amazfit off the shortlist for athletes who own more than one device or rely on an iPhone.

Multi-Device Activity Sync: What It Actually Does

The core function here is consolidation. Zepp OS 6 merges steps and calories across devices, so wearing your Balance Ultra for sleep and your Balance 3 for a run no longer inflates your daily totals. Garmin solved this exact problem with TrueUp back in 2016, a full decade ago. The more important question, which Amazfit has not answered clearly yet, is whether training load and recovery metrics sync across devices too. Steps and calories are the easy part. Acute load, HRV trends, and body battery equivalents are where multi-device sync either earns its place or stays cosmetic. For a triathlete who swaps between a pool watch and a daily driver, that distinction is critical. If you want a deeper breakdown of what changed between the Balance 2 and Balance 3 hardware before this update, the [full comparison is here](/en/articles/amazfit-balance-3-vs-balance-2-what-actually-changed-in-2026-2026-06-18).

Garmin's TrueUp implementation does sync training load across compatible devices, including the Fenix 8 and Forerunner 965. Coros does not offer multi-device sync at all as of mid-2026. Polar handles it through their Flow platform but only at the daily activity level, not acute load. Amazfit landing somewhere between Garmin and Polar on this metric is progress, but the exact scope of what syncs needs confirmation in firmware release notes before you make a buying decision around it.

iOS Notification Forwarding: A Regulatory Win, Not a Tech Win

Amazfit's published Q3 2026 roadmap commits to iOS Notification Forwarding for EU users in June 2026, covering the Balance 3, Balance Ultra, and one additional model. Garmin has no published date for the same feature, despite the EU regulatory framework being identical for both brands. This is not because Amazfit engineered something Garmin could not. It is because the EU forced Apple to open the relevant iOS APIs, and Amazfit moved faster to implement them than Garmin did. Garmin's silence here is genuinely puzzling given their engineering depth. For EU-based athletes checking pace alerts, interval notifications, or coach messages mid-run, this is a real daily quality-of-life improvement.

Apple Watch obviously has this natively, since watchOS runs on Apple's own stack. Whoop 5.0 still has no standalone GPS or notification forwarding, so it is not a direct comparison. The practical win for Amazfit is specifically against Garmin in the EU, where Garmin users have been waiting without a timeline. If Garmin's recent firmware track record concerns you, [the current bug list and fix status is documented here](/en/articles/garmin-firmware-bugs-in-2026-six-issues-and-confirmed-fixes-2026-06-14).

Sensors and Athletic Use Cases

The Balance Ultra uses a wrist-based PPG optical sensor array for heart rate and SpO2, which reads blood volume changes via reflected light. This is the same principle as Garmin's Elevate v5 and Polar's Precision Prime sensors. For steady-state running and cycling, wrist optical accuracy is acceptable. For CrossFit and Hyrox workouts with heavy grip involvement or rapid direction changes, chest strap pairing is still the reliable option. The Balance Ultra does support ANT+ and Bluetooth chest HRM pairing, which transmits electrical impulse data from a dedicated electrode strap rather than relying on the wrist sensor. The barometric altimeter on the Balance Ultra uses air pressure differential for elevation gain, which is standard across Garmin, Coros, and Polar flagships. GPS uses multi-band satellite reception, and in early 2026 testing by multiple reviewers, the Balance Ultra's GPS track accuracy sits close to the Garmin Forerunner 965 in open conditions but loses some precision in dense urban canyons.

For swimmers, the sync feature has limited relevance unless pool sessions are logged on one device and open-water on another. Neither the steps consolidation nor the current notification forwarding applies underwater. Recovery tracking via overnight HRV measurement is where Amazfit competes most directly with Whoop 5.0 and the Garmin Body Battery system. The Balance Ultra takes nightly HRV readings optically from the wrist, which is the same method Polar uses on the Vantage V3. Whoop uses a dedicated optical cluster with higher sampling frequency. Whether Zepp OS 6's sync improvements carry HRV baselines across devices is still unconfirmed.

What is missing is real transparency on the sync depth. Amazfit has not published a full breakdown of which metrics transfer and which stay siloed per device. The iOS Notification Forwarding is EU-only at launch, with no date confirmed for North American or Asian markets. Athletes outside Europe are getting the activity sync but not the notification feature, which cuts the update's value roughly in half for a global audience. The Zepp app itself still trails Garmin Connect and Polar Flow for long-term training load visualization and export options. CSV and GPX export work, but native third-party integrations with TrainingPeaks and intervals.icu remain less polished than Garmin's equivalents.

The verdict: these Zepp OS 6 updates matter most for EU-based athletes who own multiple Amazfit devices and use an iPhone. The Balance Ultra at its current price point undercuts the Garmin Fenix 8 Solar by a significant margin while matching it on most hardware specs. If you are a Garmin user in the EU frustrated by the notification forwarding gap, the Balance Ultra is now a credible alternative worth testing. If you are outside the EU or use a single device, the sync update is useful but not a reason to switch. Coros Vertix 3 owners get better long-term training analytics. Whoop subscribers get better recovery depth. But for the price, Amazfit just got harder to dismiss.