What Is an .sb3 File?
An .sb3 file is the standard project format for Scratch 3.0. It contains everything about your Scratch project: code blocks, sprites, costumes, sounds, and backdrops. When you click “Save to your computer” in the Scratch editor, you get an .sb3 file.
How to Export from Scratch
Open your project in the Scratch editor at scratch.mit.edu. Go to File → Save to your computer. This downloads the .sb3 file to your device. You can also export projects from the Scratch desktop app the same way.
How to Upload to PlayMaksi
Open PlayMaksi and tap the upload button. Select your .sb3 file from your device. Add a title, description, and thumbnail. Tap publish — your game is now live and playable on any phone. The whole process takes under a minute.
Tips for a Great Upload
Use a descriptive title that tells players what the game is about. Add a clear thumbnail screenshot. Write a short description explaining how to play. Tag your game with relevant categories so other players can discover it.