This only works if the ZIP contains the correct internal structure ( project.json at the root). If it’s just a random ZIP file, renaming it will not create a working Scratch project.
Scratch 3.0 uses the .sb3 extension to package project assets—like JSON code, SVG/PNG costumes, and WAV/MP3 sounds—into a single compressed file. 🛠️ How to Convert Zip to SB3 convert zip to sb3
Once the new .zip is created, follow the renaming steps in Method 1 to change the extension to .sb3 . Method 3: Using Online Conversion Tools This only works if the ZIP contains the