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Android Vitals Slow Sessions Tracking

Android Vitals now flags 'slow sessions' in games below 20 FPS, and Play will start steering users away — what to instrument before it bites.

Performance

Google Play Console has a new Android Vitals metric for games called Slow Sessions, and it works differently to every frame-rate metric that came before it. A session counts as slow once more than 25% of its frames take longer than 50ms to draw — the equivalent of dropping below 20 frames per second — with a second, stricter threshold tracking the 30 FPS line at 34ms per frame. Google has said Play will, in due course, start steering users away from games that can’t hold 20 FPS on their device. That turns a smoothness problem that used to just annoy players into a distribution problem that shows up as a drop in organic installs, with no crash, no ANR, and no error log to point at.

The reason this catches teams out is that Slow Sessions measures something existing performance dashboards don’t. Crash-free rate, ANR rate, and even a custom FPS counter tell you whether the game ran — Slow Sessions tells you whether it ran acceptably from the moment Android Vitals starts sampling, one minute into a session, using SurfaceFlinger frame-presentation timing rather than anything the game code reports itself. A studio can have a healthy crash-free rate and zero ANRs while still bleeding organic discoverability because a meaningful share of sessions on low-end or thermally-throttled devices never clear 20 FPS. Without device-segmented frame-timing data of your own, the first sign of a problem is a quiet decline in Play Store impressions and installs that’s easy to misread as a seasonal dip or an ASO issue.

Data Points to Track

  • Frame presentation interval per session, measured the same way Android Vitals measures it — time between consecutive frames drawn on the app’s surface — not just an average FPS number that can hide a bad tail
  • Percentage of frames exceeding the 50ms and 34ms thresholds per session, so you can see both the 20 FPS Play-enforced line and the stricter 30 FPS line before Google’s dashboard shows the aggregate
  • Device model, chipset, and thermal state at time of slow frames, since slow sessions cluster hard on specific low-end or overheating hardware rather than spreading evenly
  • Session length before the slow-frame threshold is crossed, to distinguish a brief loading-screen stutter from sustained jank through core gameplay
  • Play Store impressions and organic install trend for titles flagged in Android Vitals, tracked from the date a Slow Sessions warning first appears in Play Console

Setup Steps

  1. Instrument your own frame-presentation timing using the platform’s frame metrics APIs, matching Android Vitals’ one-minute warm-up window so your numbers are directly comparable to what Play Console reports.
  2. Bucket every session by device model and chipset tier at ingestion time, not in a later join, since the fix for a slow session on a three-year-old mid-range phone is rarely the same fix as for a thermally-throttled flagship.
  3. Compute both the 20 FPS and 30 FPS slow-frame percentages per session rather than a single blended average, so you can see which threshold is actually at risk of tripping Play’s steering behaviour.
  4. Pull Android Vitals’ Slow Sessions report into release QA alongside crash-free rate and ANR rate, checked before every rollout stage, not just after a user complaint.
  5. Set an internal warning threshold below 25% — for example 15% of frames slow — so a regression is caught in an internal or staged rollout before it reaches Android Vitals’ own flagging line.

Actionable Insights

If slow sessions concentrate on a small number of device models rather than spreading across your install base, that’s a targeted optimisation — profile that hardware specifically rather than tuning the whole render pipeline blind. If the slow-frame rate rises sharply after a specific build, correlate it against that release’s asset or shader changes before assuming it’s a device issue. And if Play Store impressions or organic installs dip for a title that Android Vitals has already flagged for Slow Sessions, that’s strong evidence Google’s steering behaviour is live for that app — the response is a performance fix shipped urgently, not a store-listing or ASO change.

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