How to Fix a WebGL Game Running Slow After Many Level Restarts

The first playthrough is fast; by the tenth restart the game crawls. WebGL resources are not reclaimed by JavaScript garbage collection, so every restart leaks GPU memory unless you delete objects yourself. Here is the cleanup pass to add.

How to fix it

1. Delete GL objects explicitly

Before reloading, call gl.deleteTexture, gl.deleteBuffer, gl.deleteFramebuffer, and gl.deleteProgram on everything the previous level created. Dropping the JS reference alone does not free GPU memory.

2. Track resources per scene

Keep a list of GL objects allocated for the current level so teardown is a single loop, rather than hoping garbage collection finds them.

3. Watch context memory

Use the browser's GPU memory tooling or WEBGL_debug_renderer_info plus heap snapshots to confirm texture count climbs across restarts and returns to baseline after the fix.

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.