Google quietly opened the door to one of the bigger health features on its wearables in a new market this week, and it did it through app release notes rather than a press release.
Version 5.10 of the Google Health app, rolling out for Android and iOS since October 9, switches on irregular rhythm notifications in Japan. That means Pixel Watch and Fitbit owners in the country can now have their heart rhythm checked in the background for signs of atrial fibrillation, which is the same job the feature has done in the United States for a couple of years.
Japan is not a small addition. It is a market where Apple's equivalent feature has been cleared since 2020, and where selling an AFib alert means going through medical device regulators first. So this is a real clearance, not a software toggle.
What Google Actually Shipped
The release notes for 5.10 list three changes, and the Japan rollout is clearly the headline:
- Irregular Rhythm Notifications in Japan. Available on Pixel Watch and Fitbit devices, analyzing heart rhythm data in the background while you are still or asleep to check for signs of AFib. Users set it up in the Health tab of the Google Health app.
- A better Readiness Score. The score now pulls in additional signals from your sleep rather than leaning mostly on recovery and activity data.
- Delete logged entries by chatting. If you logged something with the Google Health Coach by mistake, you can now ask the coach to remove it, for example "Delete the run I logged this morning." It covers daily entries such as workouts, meals, weight and symptoms. Medical records are excluded.
None of that is a redesign. It is the kind of update Google has been shipping monthly since the Fitbit app was folded into Google Health, and the pattern matters: the app is doing more of the thinking, and the hardware is doing less.
How the AFib Feature Works
Irregular rhythm notifications are passive. You are not asked to run a test or hold still for 30 seconds. The watch samples your heart rhythm while you are resting or sleeping, looks for patterns consistent with atrial fibrillation, and pings you if it finds something.
The important caveat is the same one Google and Apple both print. This is a screening feature, not a diagnosis. It can tell you your rhythm looked off and point you toward a doctor. It cannot tell you that you have AFib, and it cannot catch every episode.
Compared with an ECG reading you trigger yourself, this runs all night and costs you nothing in battery terms you would notice. If you own a Pixel Watch and have never opened the health checks section, the feature has probably been sitting there waiting.
Japan Was the Last Big Hole
This is where the comparison with Apple gets uncomfortable for Google. Apple's ECG app and irregular rhythm notifications cleared Japanese regulators in September 2020, when Japan's medical authorities approved them on the Apple Watch Series 4 and Series 5. That is six years of head start in a country with an aging population, a strong smartwatch market, and a regulatory system that treats heart-rhythm alerts seriously.
The gap is not only about Japan. Google has been slower to expand its health features country by country than Apple has, and the reasons are mostly the same everywhere: each market needs its own clearance, and each clearance takes time. The difference is that Apple has been doing this since 2018, and Google only started shipping mainstream AFib detection on Pixel Watch in the last few years.
If you are in Japan and you have been waiting on this, the wait is over as of this rollout. Everyone else gets the Readiness Score and chat-deletion changes, which land wherever the app is already available.
Google Health Is Becoming the Product
Two things stand out about this release beyond Japan.
First, the feature set keeps drifting away from the watch and into the app. Readiness Score improvements are server-side analytics. Chat-based log deletion is a Gemini-era interface change. Neither needs new hardware. That is a deliberate strategy for a platform that gets a new watch once a year at best, and it explains why Google can keep announcing updates while selling very similar hardware to last year's models.
Second, the October update for older Pixel Watch models already showed that Google is willing to push meaningful software to hardware it has stopped selling. Combine the two and you get a platform where the watch you bought two years ago is a better product now than it was at launch, which is the opposite of how most of the watch industry works.
The one thing Google still has not done in Japan is the feature that would matter most: loss of pulse detection. That cleared the US FDA for the Pixel Watch 3, and it has not been rolled out broadly. Expect that to be the next long country-by-country process.
What This Means If You Are Shopping
The practical read is straightforward. If AFib screening is the reason you are considering a Pixel Watch, the hardware you need is not exotic:
- The current Pixel Watch 5 handles the full feature set, and it is listed on Amazon at the usual discount spread against Google's own store.
- The cheaper route is a Fitbit tracker, since the release notes group "Pixel Watch and Fitbit devices" together. The screenless Fitbit Air at $99 is on Amazon too, and it now feeds the same Google Health app that Pixel Watch does.
Apple's Japan rollout in 2020 is a good reminder that this stuff arrives by clearinghouse, not by product cycle. If your country is not on the list yet, it will probably get there eventually. But "eventually" has been Google's weak spot in health features, and Japan just moved off the list after a long wait.
The Bottom Line
Irregular rhythm notifications on Pixel Watch and Fitbit are now live in Japan, and that is a bigger deal than the release notes make it sound. It closes a six-year gap with Apple in one of the world's most important wearable markets, and it puts Google's AFib screening in front of a population that stands to benefit from it most.
The rest of 5.10 is housekeeping: a Readiness Score that finally uses your sleep, and a coach you can tell to undo something. Solid improvements, neither one worth upgrading for. If you have been holding off on a Pixel Watch specifically because the heart-rhythm feature was missing where you live, that argument just got weaker.
Sources: Google Health app 5.10 release notes (rollout began October 9, 2026); Google Health Help Center documentation on irregular rhythm notifications; Google Pixel Watch support pages; write-ups at 9to5Google, Droid-Life, Jetstream and AndroidPure; MacRumors and iDownloadBlog coverage of Japan's September 2020 approval of Apple's ECG app and irregular rhythm notifications. Google has not issued a press release on the Japan rollout, and no regulator filing has been published for it, so the feature availability rests on Google's own release notes.
