If you edited any images or audio files while they were unzipped, ensure they maintain their exact original filenames (e.g., 83a15b...svg ) and are not corrupted.
Check the box next to (this ensures you can see and edit the .zip part). Right-click your ZIP file and select Rename . Change the .zip text at the end of the filename to .sb3 .
: This usually happens if your ZIP file contains a folder. Scratch requires the project.json to be at the "top level" of the archive. convert zip to sb3
Advanced users sometimes open the project.json file in a text editor (like VS Code or Notepad++) to mass-edit variables, fix corrupted blocks, or inject custom data.
If you rename your file to project.sb3 but it still displays a zipper icon and opens as a folder, your operating system is hiding the real file extension. It is likely named project.sb3.zip . If you edited any images or audio files
Right-click (or Control-click) the file and choose . Expand the Name & Extension section. Delete zip and type sb3 in its place.
If your file was originally an .sb3 project that was renamed to a .zip (or compressed directly from Scratch assets), you can convert it instantly by changing the extension. On Windows: Open and locate your .zip file. Change the
If you have a ZIP archive that contains the necessary Scratch project files, follow these steps to "convert" it: