CotEditor: An open source plain-text editor for macOS

CotEditor is a lightweight, fast and open-source plain text editor made specifically for macOS.

CotEditor comes with powerful options out of the box: syntax highlighting, split editor, auto backup and more. Check out a full list of features below.


  • Syntax Highlighting – Colorize more than 50 pre-installed major languages like HTML, PHP, Python, Ruby or Markdown. You can also create your own settings.
    Split Editor – Split a window into multiple panes to see different parts of your document at the same time.
  • Powerful Find & Replace – Super powerful find and replace using the ICU regular expression engine.
  • Character Inspector – Inspect Unicode character data of each selected character in your document and display them in a popover.
  • Setting via Click – There are no complex configuration files that require geek knowledge. You can access all your settings including syntax definitions and themes from a standard preferences window.
  • Scriptable – Make your own macro in your favorite language, whether it is Python, Ruby, Perl, PHP, UNIX shell, AppleScript or JavaScript.
  • Auto Backup – You don’t need to lose your unsaved data anymore. CotEditor backups your documents automatically while editing.
  • Incompatible Characters – Check and list-up the characters in your document that cannot convert into the desired encoding.
  • Outline Menu – Extract specified lines with the predefined syntax, and you can jump to the corresponding line.
  • CJK Language Friendly – Estimate various file encodings accurately, toggle to vertical text mode and keep its line height correctly.

You can download CotEditor from GitHub or the Mac App Store. A third option would be to install CotEditor with Homebrew.

Check out this article to learn how to install and use Homebrew on your Mac.

CotEditor is free and open source and requires macOS Monterey or later.