Convert Zip To — Sb3
Several online tools allow you to convert ZIP files to SB3. Here's how:
Assuming files are in folder scratch_project/ with project.json and assets/:
cd scratch_project
zip -r ../project.sb3 .
Then open or rename as needed (the .zip produced is already correct; give it .sb3 extension if desired).
If you renamed your Zip to SB3 and Scratch gives you an error, the review is simple: Your Zip file was not structured correctly.
To verify this:
If you have a folder full of Scratch assets (sprites, sounds, costumes, and JSON code) or a modified project archive, you may need to convert it into an SB3 file to upload it to the Scratch website or open it in the Scratch app.
The good news? An SB3 file is actually a standard ZIP archive with a different file extension. Here’s how to convert one to the other.
Converting a ZIP to SB3 isn't just a file conversion—it's an act of transparency. It reveals that Scratch is built on open web standards: JSON for logic and standard image/audio formats for media.
Next time you see a .sb3 file, remember: It's just a .zip file waiting to be unzipped.
Converting a ZIP file to an SB3 format is essentially just a matter of renaming the file extension, as SB3 files are actually compressed ZIP archives containing Scratch 3.0 project data. Why Convert ZIP to SB3?
This process is usually necessary when you have manually modified a Scratch project's internal components—such as its project.json file or individual assets like sprites and sounds—and need to repackage them so they can be reopened in the Scratch editor. Conversion Methods 1. Manual Renaming (Recommended) convert zip to sb3
Since an SB3 file is a renamed ZIP archive, you can perform the conversion manually:
Ensure proper structure: All project files (like project.json and asset folders) must be at the root of the ZIP file, not inside a subfolder within the archive.
Rename the extension: Right-click your ZIP file and change the .zip extension to .sb3.
Confirm the change: If your operating system warns about changing file extensions, click "Yes" or "Use .sb3". 2. Online Converters
If you prefer a tool-based approach, several online platforms automate this for you:
ezyZip: Allows you to drag and drop a ZIP file and extract or convert its contents specifically into the SB3 format.
Sendeyo: A straightforward online file converter that supports various archive-to-project transitions. Understanding the SB3 Structure
When you successfully convert and then "unzip" an SB3 file to look inside, you will typically find:
project.json: The core file containing all scripts, variables, and metadata for the project.
Asset Files: Images (costumes/backdrops) and audio files (sounds), often named with MD5 hashes like b73...png or a12...wav. Troubleshooting Several online tools allow you to convert ZIP files to SB3
"Failed to upload" error: This usually happens if the project.json file is missing or if the ZIP was created by compressing a folder rather than the files inside the folder.
Version Issues: If you are trying to convert files from older Scratch versions (SB or SB2), simply renaming them to SB3 may not work; you should instead use the Scratch 3.0 Editor to "Load from your computer" and then "Save to your computer" to update the format automatically.
Are you planning to manually edit the project's code inside the ZIP before converting it back to SB3? Convert .zip to .sb3? - Discuss Scratch
How to Convert ZIP to SB3: A Complete Guide for Scratchers Converting a ZIP file to SB3 is a common task for Scratch developers who want to modify project assets or manually reconstruct a project file. Because an .sb3 file is essentially a renamed ZIP archive containing a project.json file and various media assets, the process is straightforward once you understand the internal structure. Understanding the SB3 Format
The .sb3 file format was introduced with Scratch 3.0. Unlike earlier versions, it is a ZIP-based archive that bundles everything your project needs into one file. Inside a standard SB3 file, you will find: project.json: The core code and metadata for your project.
Asset Files: Various .svg, .png, .wav, or .mp3 files named with MD5 hashes that represent your costumes and sounds. Method 1: The Manual Renaming Technique (Fastest)
If your ZIP file already contains the correct Scratch project structure (with the project.json at the top level), you can "convert" it simply by changing the extension.
Locate your ZIP file: Ensure it contains the project.json and assets directly in the root directory, not inside a subfolder. Rename the Extension:
Windows: Right-click the file and select Rename. Change the ending from .zip to .sb3. If you don't see the extension, enable "File name extensions" in the View tab of File Explorer.
Mac: Click the file name once to edit, or right-click and choose Rename. Change .zip to .sb3 and confirm the change in the prompt. Then open or rename as needed (the
Upload to Scratch: Open the Scratch Editor, go to File > Load from your computer, and select your new SB3 file. Method 2: Manual Re-compression (For Modified Files)
If you have extracted a project to edit its code or swap assets, follow these steps to ensure it packages correctly:
Open your project folder: Make sure you are looking at the individual files (project.json and the assets).
Select All Files: Do not zip the parent folder itself. Instead, select all the files inside the folder.
Compress to ZIP: Right-click and choose Compress or Send to > Compressed (zipped) folder.
Rename: Change the resulting archive name from Archive.zip to YourProjectName.sb3. Method 3: Using Online Tools and Packagers
Sometimes "converting" means turning a packaged project (like an EXE or HTML file) back into a Scratch-editable format.
TurboWarp Unpackager: If you have a ZIP file generated by a packager, the TurboWarp Unpackager can often extract the original Scratch project from it.
TurboWarp Packager: To go the other direction (from SB3 to a ZIP containing an executable), use the TurboWarp Packager. Troubleshooting Common Errors
"Failed to upload": This usually happens if your ZIP file contains a folder. Scratch requires the project.json to be at the "top level" of the archive.
Missing Assets: If your project loads but has white squares or no sound, ensure all MD5-named files from the original ZIP were included in your new SB3 compression.
Extension not changing: If the file remains a ZIP (e.g., project.sb3.zip), you must disable "Hide extensions for known file types" in your OS settings to properly change the format. what does sb3 mean - Discuss Scratch