Godot Web Export Not Working: SharedArrayBuffer and Blank Page

How to fix it

Try these in order — the most common fix is first.

1. 1. Use single-threaded export

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   1. In the Web export preset, turn off Use Threads (single-threaded is the default since 4.3)
   2. This needs no special headers and works on itch.io
   Did this fix it? Yes No

2. 2. Serve the required headers or enable PWA

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   1. Send Cross-Origin-Opener-Policy: same-origin and Cross-Origin-Embedder-Policy: require-corp
   2. Or enable Progressive Web App > Enable in the export preset
   3. Test locally with Godot's serve.py, not by opening the file
   Did this fix it? Yes No

3. 3. Check renderer and platform limits

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   1. Use the Compatibility renderer for web
   2. Godot 4 C# projects cannot export to the web
   3. Keep exported file names unchanged, index.html included
   Did this fix it? Yes No

4. 4. Clear cache and read the console

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   1. Open DevTools (F12) and read the console errors
   2. In Application, unregister the service worker and reload
   3. Audio needs a user click first in many browsers
   Did this fix it? Yes No

Symptoms

Exported HTML5 game shows a blank page, a 'SharedArrayBuffer' or cross-origin isolation error, or no sound until clicked.

Why it happens

• Threaded export without Cross-Origin-Opener-Policy and Cross-Origin-Embedder-Policy headers
• Not served over HTTPS or opened as a local file
• Renderer is not Compatibility
• Project uses C#, which Godot 4 cannot export to the web
• Cached service worker serving an old build

This guide also covers

• godot web export not working
• godot html5 export blank page
• godot sharedarraybuffer error
• godot web export itch.io
• godot web export c#

The same problem in other apps

All export, render & quality loss guides →

• Unity Build Failed (Unity)
• Unreal Engine Shaders Compiling Forever (Stuck at 45%) (Unreal Engine)

Other Godot errors

• Godot No Export Template Found at the Expected Path
• Godot Android Export Failed (JDK, SDK and Keystore Errors)
• Godot 4 Crashes on Startup: Vulkan Device Errors
• Godot C# Error: Godot.NET.Sdk or .NET SDK Not Found
• Godot 3 to 4 Upgrade: Project Errors After Converting
• Godot Shader Compilation Stutter and Lag on First Run
• Godot Invalid Access to Property on Null Instance Error
• Godot Exported Game Blocked on macOS: Developer Cannot Be Verified