A tester that never gets tired
Players do things you never planned: they hold two keys at once, mash jump, pause during a cutscene, click everywhere on the title screen. The Bug Finder is a bot that plays your game that way, fast and without stopping, and writes down everything that goes wrong. It is a monkey test, the oldest trick in game QA, made easy: drop your web build, pick how the bot should play and press Start.
What it finds
| Problem | How it is found |
|---|---|
| Crashes and script errors | Every uncaught error and failed promise in the game, with the stack trace. |
| Error and warning logs | Godot errors, Unity exceptions and console errors and warnings, grouped by message. |
| Freezes and stutters | Frames that take longer than a quarter of a second, and freezes of 1.5 seconds or more. |
| Missing files | Any file the game asks for that is not in the build, like a sound or a level. |
| FPS drops | The frame rate every second, drawn as a chart, with the low points marked. |
| Memory leaks | Memory that keeps growing while the game runs (in Chrome and Edge). |
| Black or stuck screen | A screen that stays black, or does not change at all for 20 seconds while the bot plays. |
| Lost graphics | The WebGL context being lost. |
Repeat the bug
Each problem shows a screenshot from the moment it happened and the last inputs the bot sent before it, like "hold → 600 ms, tap Space, click at 320, 180". Do the same and you can usually see the bug yourself. Copy the report and paste it into GitHub, Trello or Discord. With Pro, Replay sends exactly the same inputs again, so you can check that your fix works.
How to export your game for the web
Godot 4: Project > Export > Add Web, then Export Project into an empty folder. Leave Thread Support off. Unity: File > Build Settings > WebGL > Build. In Player Settings > Publishing, set Compression Format to Disabled or Gzip, or turn on Decompression Fallback. Phaser, PixiJS, Construct, GameMaker HTML5: use the folder with index.html. Drop the whole folder, or a ZIP of it.
Is my game uploaded?
No. The files are stored only in this browser and the game runs here. Test only builds you made or trust, because the game runs on this page. When the game freezes for a long time this tab freezes with it, because the game shares the page. If the tab stops responding completely, that is a sign of an endless loop in the game.