: The internal folder structure of your ZIP file is incorrect. Specifically, the project.json file might not be directly at the root level of the archive. The Fix : Follow the "Create a New Project" method outlined in the manual section. Make sure you compress only the contents of the folder, not the folder itself. When you open the new .sb3 file with an archive tool, you should immediately see project.json and asset files, not a single folder.
Once you have your SB3 file (whether converted via an online tool or the manual method), you're ready to use it in Scratch. The process to import it is simple:
“This project is corrupted.” Fix: Open project.json in a text editor. Look for missing commas, brackets, or unescaped characters. Validate at JSONLint.com .
Right-click the file and select (or press Cmd + I ). Under the Name & Extension tab, delete zip and type sb3 . convert zip to sb3
You extracted the SB3 file to manually swap out a sound file or edit a costume image using advanced external software like Photoshop or Audacity.
Follow these platform-specific steps to ensure your files are compressed perfectly for Scratch. Method 1: Windows (No Software Required)
Ensure you did not zip the main folder container. You must select the items inside the folder and zip them directly. If Scratch sees a folder inside the .sb3 archive instead of project.json right at the root level, it will fail to load. : The internal folder structure of your ZIP
Sometimes manually inspecting the project.json is the only way to find why a project won't load. If you'd like, let me know: Did you manually edit the files inside the ZIP?
In this guide, we’ll break down exactly what these files are and the foolproof ways to convert your ZIP archive back into a working Scratch 3.0 project. What is an SB3 File?
If you’ve been working with —the popular visual programming language from MIT—you’ve likely encountered two file types: .sb3 (the standard project file) and .zip (a compressed folder). But what happens when you download a project from a website, receive a file from a friend, or recover a backup, only to find a ZIP archive instead of an SB3 file? Is it possible to “convert” one to the other? Make sure you compress only the contents of
Converting a ZIP file to SB3 is a straightforward process, whether you use online conversion tools, Scratch's built-in features, or manual extraction and import. By following these steps, you can easily import media files from a ZIP archive into your Scratch project.
, costumes, and sounds), you can convert it by manually changing the file extension: Locate your ZIP file in your computer's file explorer. Right-click the file and select Change the extension project.zip project.sb3 Confirm the change
