Open a browser and go to a free online tool like or any JSON validator. Paste your code into the validator and click Validate JSON .
: The asset files are not named "cat.png." Instead, they are named after their MD5 hash values (e.g., b7a6c9...svg ) so Scratch can locate them accurately. Step-by-Step: Converting ZIP back to SB3
The tool will point out the exact line number where a bracket, brace, or comma is missing. Fix it, save the file, and re-compress. Fix 2: Repair Missing Assets convert zip to sb3 fix
This usually means the project.json file is corrupted or missing.
If you have a folder full of Scratch project files (like project.json , sounds, and costumes) zipped together, you might think simply renaming the .zip to .sb3 will work. Sometimes it does. Often, it fails. Open a browser and go to a free
Right-click the highlighted files and select Compress to ZIP file (Windows 11) or Send to > Compressed (zipped) folder (Windows 10).
: He unzips his current file into a fresh folder. Step-by-Step: Converting ZIP back to SB3 The tool
# Batch rename for f in *.zip; do mv "$f" "$f%.zip.sb3"; done
If you are still having trouble, the best fix is to re-download the project from the Scratch website or check if the project.json file is corrupted.
This is where most people fail. Do not zip the parent folder.
How to Convert ZIP to SB3 (and Fix Common Errors) Scratch is an excellent platform for creating games, animations, and interactive stories. However, managing Scratch project files can sometimes be frustrating. If you have downloaded a Scratch project or compressed one yourself, you might end up with a .zip file instead of the native .sb3 format. Trying to upload this ZIP file directly to Scratch will result in an error.
