Exporting a browser build from your engine

A browser build is a folder with an index.html file in it. Whatever tool you use, export for the web, then upload that folder.

Plain HTML and JavaScript (including AI-written games)

Put index.html at the top of the folder and keep every other file beside it or in sub-folders. Use relative addresses (js/game.js, not /js/game.js), because the game runs inside a folder on our play address.

Unity

• File › Build Settings › WebGL, then Build.
• In Player Settings › Publishing Settings, any Compression Format works: Disabled, Gzip or Brotli. We serve the compressed files the way browsers expect.
• Upload the output folder, the one that contains index.html, Build and TemplateData.

Godot

• Project › Export › Add › Web, then Export Project and name the file index.html.
• Godot 4 exports that use threads need a page of their own. We notice this automatically and open your game in a new tab; you can also tick Open this game in its own tab under Game details. To run inside the game page instead, turn Thread Support off in the export settings.
• Godot 3 exports run inside the game page.

GameMaker and Construct

Export for HTML5. Unzip the result if you want to check it, and upload the folder that contains index.html.

Unreal Engine

Current versions of Unreal no longer export for the browser. Publish Unreal games as downloads.

Check it before you upload

Open the folder with a small local web server and make sure the game starts and that nothing fails to load. If it works there, it will work here. Opening index.html by double-clicking is not a good test, because browsers block many things for files opened that way.