.m4 file: how to open it on Windows

2 Windows apps register the .m4 extension. Install one of them to open the file with a double-click.

About the format

Format

M4 macro

MIME type

application/x-m4

Format data: freedesktop.org shared-mime-info and PRONOM (The National Archives, UK).

• 
  Notepad3

  Notepad like text editor based on the Scintilla source code.

  Free 7.26.602.1 84.4K ↓ ★ 6.7K
• S
  Sublime Text 4

  Sublime is a sophisticated cross-platform text editor for code, markup and prose.

  Proprietary 4.0.0.421500

Related guide: Change the default app for a file type in Windows