demo · v133

Save-on-freeze pattern

A draft note that saves itself the moment the page hits freeze. Switch tabs with OS Energy Saver on, come back — the draft is still there.

state: active
freeze events fired
0
resume events
0
last saved bytes
0
last save (UTC)

the lifecycle that energy-saver freeze adds

With Energy Saver active, Chrome 133+ now freezes hidden & silent same-origin frame groups after 5 minutes if they exceed a CPU threshold. Once frozen, your code does not run. The window to persist unsaved state is the freeze event itself.

document.addEventListener("freeze", () => { saveDraftSync(); });
document.addEventListener("resume", () => {});
addEventListener("pagehide", () => saveDraftSync());

see also