v139 · performance

Faster background freezing on Android

Shortens the time to freezing background pages (and associated workers) from 5 minutes to 1 minute on Android. See the original intent to ship for background: https://groups.google.com/a/chromium.org/g/blink-dev/c/NKtuFxLsKgo/m/XmQganj9EAAJ. Android 15 has introduced a 1 minute background network restriction on apps, and faster background

concepts

  1. Freeze Timeline

    Background tabs on Android freeze sooner — within ~1 second of backgrounding, down from 5. Save more aggressively on the freeze event; opt into Background Sync where you need work to continue.

  2. Lifecycle Recorder

    Live log of visibilitychange, freeze, and resume events on this tab. Switch away or lock your phone and come back — see exactly which signals you can hook to persist state before the freeze.

  3. Freeze Budget Explainer

    Side-by-side timelines comparing the v138 (5-min) and v139 (1-min) budgets. Pick a workload — polling, WebSocket, Service Worker fetch, silent audio — and see the impact narrated.

  4. Freeze Savings Calculator

    Enter number of open tabs, memory per tab, and CPU usage — see the memory and CPU freed by faster freezing. A timeline visualization marks the old 5-minute and new 1-minute freeze points, with a "simulate tabs going background" animation.

why it shipped

See the original intent to ship for background: https://groups.google.com/a/chromium.org/g/blink-dev/c/NKtuFxLsKgo/m/XmQganj9EAAJ

references