Convert SB2 to SB

An old Scratch 1.4 installation, classroom archive, or Scratch-based application may require a project in .sb format instead of .sb2. Scratch does not provide a complete built-in downgrade path, so the project must be converted with a specialized utility or rebuilt in Scratch 1.4.

What the SB2 format is

.sb2 is the native project format of Scratch 2.0, used by the former Scratch 2.0 web editor and the Scratch 2 Offline Editor. It is a ZIP-based package containing project data, sprites, scripts, costumes, sounds, variables, and metadata. Scratch 2 projects are common in older educational archives and downloads created before Scratch 3 introduced .sb3.

Students, teachers, researchers, and archivists typically encounter SB2 files when preserving or reopening projects created with Scratch 2.0. Renaming .sb2 to .sb does not convert the contents; the two extensions use different internal formats.

What the SB format is

.sb is the native project format used by Scratch 1.0 through 1.4. It is a serialized Squeak/Smalltalk project file that stores the stage, sprites, scripts, media, variables, and project settings in one file. Scratch 1.4 can open and save SB files, but it cannot directly open an SB2 package.

SB is useful when the destination is Scratch 1.4, software based on the Scratch 1.x engine, or a legacy collection that explicitly requires the format. It is not a smaller or more modern replacement for SB2; conversion normally reduces feature and compatibility support.

How to convert SB2 to SB

Try a purpose-built converter first. The community utility commonly known as Retro Converter has been used for partial Scratch 2-to-1.4 migration. Availability and compatibility can change, so obtain it only from a maintained project page or trusted educational archive. Work on a copy of the SB2 file, select the SB2 input and SB output options if provided, then open the generated file in Scratch 1.4 and test every script and asset. Do not confuse an SB2-to-SB3 converter with an SB2-to-SB converter.

There is no reputable general-purpose online converter that reliably converts every SB2 project to SB. Generic file-conversion websites usually do not understand Scratch project structures, may only change the filename or package type, and require uploading project assets. Use an online service only when it explicitly documents SB2-to-SB support, identifies the conversion engine, and explains how uploaded files are deleted.

If automated conversion fails, rebuild the project in Scratch 1.4:

1. Keep an untouched backup of the original .sb2 file.
2. Install Scratch 1.4 and, when needed, the archived Scratch 2 Offline Editor from an official Scratch archive or trusted institutional mirror. The old Scratch 2 editor may require Adobe AIR or an older operating system.
3. Open the SB2 project in the Scratch 2 editor with File → Open. Record the stage layout, sprite positions, scripts, variables, lists, costumes, sounds, and project properties.
4. Create a project in Scratch 1.4 and recreate the stage and sprites. Copy the logic manually, replacing blocks that have no Scratch 1.4 equivalent.
5. Extract or export compatible media from the source and import it through Scratch 1.4. SB2 is a ZIP package, so a copy can usually be inspected with an archive utility after changing its copy's extension to .zip; do not edit the original package in place.
6. Check costume scale and rotation centers, sprite coordinates, sound format and volume, broadcasts, variables, lists, timing, and collision logic.
7. Use File → Save in Scratch 1.4. The program writes the completed project as an .sb file.

Compatibility and quality limits

Scratch 1.4 cannot natively represent Scratch 2 features such as custom blocks, clones, several newer sensing and list behaviors, or Scratch 2 extensions. Cloud variables and other server-dependent behavior cannot remain functional offline. Unsupported blocks require redesigned logic, not simple text replacement.

Automated tools may omit scripts, alter block behavior, lose metadata, or import only a subset of media. Scratch 1.4 also handles images, sound codecs, volume, scaling, and sprite rotation differently. Treat the conversion as complete only after opening the SB file in the intended Scratch 1.4 environment and testing the project's scenes, broadcasts, variables, lists, sounds, and controls.