Visual programming language

Filetypes[edit]

In version 1.4, an .sb file was the file format used to store projects.^[48]

An .sb file is divided into four sections:

• 
  "header", this 10-byte header contains the ASCII string 'ScratchV02' in versions higher than 1.2, and 'ScratchV01' in versions 1.2 and below
  
• 
  "infoSize", encodes the length of the project's infoObjects. A four-byte long, 32-bit, big-Endian integer.
  
• 
  "infoObjects", a dictionary-format data section. It contains: "thumbnail", a thumbnail of the project's stage; "author", the username of the project's creator; "comment", the Project Notes; "history", the save and upload log; "scratch-version", the version of Scratch used to save the file;
  
• 
  "contents", an object table with the Stage as the root. All objects in the program are stored here as references.
  

Version 2.0 uses the .sb2 file format. These are zip files containing a .json file as well as the contents of the Scratch project including sounds (stored as .wav) and images (stored as .png).^[49] Each filetype, excluding the project.json, is stored as a number, starting at 0 and counting up with each additional file. The image file labeled '0.png' is always a 480x360 white image, but '0.wav' will still be the earliest non-deleted file.

The ScratchX experimental version of Scratch used the .sbx file format.^[50]

Scratch 3.0 uses the .sb3 format, which is very similar to .sb2.^[51], one difference being the sound.