Running 3 and 4 Side by Side
Sublime Text 4 will use the same data directory as Sublime Text 3, so it will pickup exactly where you left off in version 3. You can configure this, however. Sublime Text 4 chooses what data directory to use by:
If the ST4 data directory exists, use that
Otherwise, if the ST3 data directory exists, use that
Finally, if neither exist, create the ST4 data directory
To keep ST4 and ST3 using different data directories, you’ll need to manually create the ST4 one. The exact path for this directory depends on your operating system:
Windows: %APPDATA%\Sublime Text
Mac: ~/Library/Application Support/Sublime Text
For reference, the ST3 data directory is in the same location, but has a
on the end.
On Mac, the ~/Library directory is hidden by default. To navigate there, select the menu item in Finder, and type in ~/Library.