demo · v139
Freeze Savings Calculator
Chrome 139 freezes backgrounded Android tabs after ~30 seconds instead of ~5 minutes. Dial in your scenario to see how much memory and CPU that frees — and watch the tabs freeze in real time.
6 tabs
80 MB
5 %
5 min
pre-v139 freeze delay
time wasted running in background before freeze
30 s
v139 freeze delay
time running in background before freeze
4.5 min
savings window
time Chrome 139 saves per tab per background session
—
MB freed in 5 min
across all tabs, compared to no-freeze baseline
—
% CPU freed
cumulative CPU released across all tabs after 30 s
—
est. battery impact
relative improvement (tabs * CPU * window)
// freeze window = 300 s (old) − 30 s (new) = 270 s saved per tab
mem freed = 6 tabs × 80 MB × (300 − 30) / 300 = — MB
cpu freed = 6 tabs × 5 % × (270 / 300) = — %
battery score = tabs × cpu% × 4.5 min = —
time until freeze — 5-minute window
pre-v139
v139
tab simulation — backgrounded tabs freezing
Feature detection: checking…
the code
// Detect page lifecycle support
const supported = 'wasDiscarded' in document;
document.addEventListener("visibilitychange", () => {
if (document.visibilityState === "hidden") {
// v139: you have ~30 s before Android freeze
// pre-v139: you had ~5 minutes
flushAnalytics();
}
});
document.addEventListener("freeze", () => {
// last chance before CPU is pulled
persistCriticalState();
});
// On resume, check if we were discarded
if (document.wasDiscarded) {
restoreFromStorage();
}