Quick answer: Listen for the visibilitychange event and re-request your animation frame when the page becomes visible again, rather than assuming rAF keeps ticking.

A player's monitor sleeps, they wake it, and your web game is frozen on the last frame. The browser throttled rAF while hidden and the loop never recovered. Restart it on the visibility event to resume play.

How to fix it

1. Restart the loop on visibility

Add a visibilitychange listener and, when document.hidden becomes false, call requestAnimationFrame again to restart a loop that was throttled to a halt.

2. Guard against double loops

Track whether a frame is already scheduled so restarting on visibility does not spawn two concurrent rAF loops running your update twice per frame.

3. Clamp the catch-up delta

On the first frame back, clamp the elapsed time so the simulation does not jump forward by the entire sleep duration.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every HTML5 error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

The errors you never hear about are the ones quietly costing you players. Visibility turns them into a worklist.