SideBySide

SideBySide is a Blender 4.5 addon for macOS that allows launching multiple independent Blender application instances — either blank new windows or specific .blend files — to enable true side-by-side editing without replacing existing open files.

Features

• Open a brand new empty Blender instance.
• Open any .blend file in a new Blender instance.
• Each instance runs as a separate macOS application process.
• Avoids default Blender macOS limitation where opening a new file replaces the current one.
• Keyboard shortcuts on macOS:
  • Command + Option + N: Open new blank instance.
  • Command + Shift + Option + N: Open .blend file in new instance.

Installation

1. Download or clone this repository.
2. In Blender 4.5, go to Edit → Preferences → Add-ons → Install.
3. Select the addon .py file and enable it.
4. Use the new menu entries under File or the keyboard shortcuts.

Usage

• File > Open New Blank Blender Instance: Opens an empty new Blender window.
• File > Open Blender File in New Instance: Opens a file browser to select a .blend file, then opens it in a new Blender window.

Requirements

• Blender 4.5 or newer.
• macOS with Blender installed in /Applications/Blender.app.

Notes

• If Blender is installed elsewhere, update the BLENDER_PATH in the addon script accordingly.
• This addon does not change how macOS or Finder open Blender files by default.
• Designed to solve Blender’s single-instance limitation on macOS by launching multiple app processes.

License

This addon is licensed under the GNU General Public License v3.

Author

tank shield