For developers, educators, or archivists looking to convert hundreds of backup ZIP files into deployable SB3 projects simultaneously, automation is required. Below is a clean Python script utilizing native libraries to ensure structural integrity and maximum output quality.
Sample rate mismatch (e.g., 48kHz forced to 22kHz). Fix: Use Audacity to re-export audio as WAV (16-bit PCM, 44100Hz) before re-ZIPping.
: A specific high-standard finish for architectural concrete (e.g., used in large-scale construction projects like the Offenbach Harbour School ).
The converter rasterized your SVGs. Fix: Open the original ZIP, locate .svg files, and re-import them manually into a new Scratch project. Then copy the scripts.
To ensure the "extra quality" and functionality remain intact: Scratch Online Editor Load from your computer Select your new Troubleshooting Quality Issues Corrupt Files zip to sb3 extra quality
If you’ve ever downloaded a Scratch project from a GitHub repository, a backup drive, or a collaborative asset pack, you’ve likely encountered the .zip format. While convenient for storage, ZIP files are useless for the Scratch 3.0 editor. To run or edit the project, you need the .sb3 file.
def zip_to_sb3_extra_quality(zip_path, output_path): # Open the original zip with zipfile.ZipFile(zip_path, 'r') as zf: # Recompress with ZIP_STORED (no compression) with zipfile.ZipFile(output_path, 'w', zipfile.ZIP_STORED) as sb3: for file_info in zf.infolist(): # Preserve UTF-8 filenames data = zf.read(file_info) sb3.writestr(file_info, data)
: Educators or developers might share Scratch projects as ZIP files for ease of distribution. Users receiving these files need to convert them back to SB3 to work on Scratch.
A collection of .svg (vector graphics), .png (raster images), and .wav or .mp3 (audio files). These represent the costumes, backdrops, and sounds used in your project. They are typically named using an MD5 hash of the file content (e.g., b7a3...png ). For developers, educators, or archivists looking to convert
The process of converting a ZIP file to an (Scratch 3.0 project file) is common for users who need to manually edit project assets—like JSON code, sounds, or costumes—and then re-import them into the Scratch Editor. Conversion Guide: ZIP to SB3
Note : Ensure "File name extensions" are visible in your operating system settings to edit the extension rather than just the name.
Convert source audio to 16-bit, 44.1 kHz WAV files before building the final package.
project.json was stripped of "extensions" array. Fix: Open the JSON in a raw editor (VS Code), find "extensions": [...] , and ensure it matches the original. Then re-zip with Store method. Fix: Use Audacity to re-export audio as WAV
: Replace large .wav files with high-quality, lower-bitrate .mp3 files to save space without a noticeable drop in sound quality .
The Scratch community is pushing for a formal . Proposed features include:
directly to perform bulk changes that would take hours in the block editor. The Quick Conversion Guide