How to Convert ZIP to SB3 (and Fix Common Errors) If you’ve ever tried to upload a Scratch project only to realize you have a .zip file instead of a .sb3 file, you’re not alone. Scratch 3.0 projects are essentially compressed archives, but the editor won't recognize them unless they have the correct extension and internal structure.
The "Double Extension" Trap: Make sure your file isn't actually named project.sb3.zip. It must end strictly in .sb3.
Metadata Restoration
(Note: The * selects all contents, not the folder itself.)
This is the most frequent mistake. If you right-click a folder and select "Compress," the computer often puts everything inside a new sub-directory within the ZIP. convert zip to sb3 fix
Upload: Go to the Scratch Editor, click File > Load from your computer, and select your new file. Method 2: Manual Re-Zipping (The "Broken Archive" Fix)
Use a dedicated repair tool: You can utilize sb3fix by TurboWarp to read and recover corrupted Scratch projects even if the ZIP directory is damaged. How to Convert ZIP to SB3 (and Fix
The Fix: Ensure there is a file named exactly project.json (all lowercase) in the archive. This file acts as the "map" for the entire project. Fix 3: Compression Compatibility