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forkphorus runs Scratch 3, 2, and 1 projects really fast by compiling them to JavaScript. Try it out by pasting a project ID or URL into the field below, selecting a project file, dropping a file on the page, or exploring the examples studio.

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forkphorus is maintained by Thomas and other contributors. It is a fork off Nathan's phosphorus. Its CPS-style compilation was inspired by Rhys's sb2.js. The JSZip library is used to read .sb2 and .sb3 files, and the canvg library is used to render SVGs for Scratch 2 projects.


The source code for forkphorus is available on GitHub.