Zip To Sb3 | Extra Quality

cd /path/to/your/unzipped/project
zip -X -r -D -q -0 myproject.sb3 project.json costumes/ sounds/

Then rename: mv myproject.sb3 myproject.sb3

Before fixing the problem, we must understand the anatomy of these files.

To achieve "Extra Quality" when converting a .zip archive to the .sb3 Scratch file format, you must pay attention to three things: Asset Integrity, Filename Accuracy, and Project Metadata. zip to sb3 extra quality

Since .sb3 files are technically just renamed .zip files containing JSON data and media assets, "quality" is determined by how well you preserve the original assets without Scratch's automatic compression downgrading them.

Here is the guide to the High-Quality conversion method. cd /path/to/your/unzipped/project zip -X -r -D -q -0

If your goal is to convert a ZIP file that contains Scratch project files into an SB3 file, here's what you need to know:

Since an SB3 is already a ZIP file, converting is simply a matter of renaming the file extension: Then rename: mv myproject

No actual compression or decompression is needed – the internal structure remains identical.

The .sb3 file is just a container. The brain is the project.json file. If your ZIP has this file, do not edit it unless you know JSON syntax. Editing this manually allows you to set high-quality settings that the Scratch editor sometimes hides.

Key JSON Quality Settings: