CotEditor is a light-weight, neat, yet powerful text editor designed for editing plain-text files such as web pages (HTML, CSS), program source codes (Python, Ruby, Perl, etc.), structured texts (Markdown, Textile, TeX, etc.), or any other kind of plain-text.
Just For Mac The application is exactly made for macOS. CotEditor looks and behaves just as macOS applications should. It means, you already know how to use it even on the first launch. There are no complex configuration files that require geek knowledge so that you can access all your settings including syntax definitions and themes from a standard preferences window.
Quick, Easy, and Powerful CotEditor launches so quick that you can write your text immediately when you want to. It's perfect for you to write a draft version of your document or a scratch code. The simply organized user interface doesn't disturb your task. However, at the same time, CotEditor is neither a software only for beginners nor a typical minimal “zen-style” editor. It is fully customizable. There are, of course, syntax highlighting feature for various languages, find and replace with the regular expression, auto-indentation, command-line tool, and lots of other deep functions. You can also easily write your own macro in your favorite languages.
Key Features • Syntax highlighting including more than 50 preset languages • Powerful find and replace with the regular expression • Auto-backup with/without overwriting actual document files • Line numbers view • Live character/word/line count • Handling file encoding and line endings with care • Auto-generated outline menu for fast navigation • Character inspector that shows the zoomed glyph and Unicode information • Vertical text layout mode • Various Unicode normalizations • Semi-transparent window • Command-line tool • Scriptable with your favorite language • JCK-languages friendly • RTL writing direction support
WHAT’S NEW Version 4.0.0: New function The new user interface is designed to adapt to macOS 11 Big Sur. Update the application icon. Redesign the document window. Support Apple Silicon. Add syntax style to Dockerfile.
Improvements Change the system requirements to macOS 10.15 Catalina and higher. Move the end of line/file encoding menu from the toolbar to the status bar. Change the default setting of the item to be displayed in the toolbar/status bar. Change the default theme from Dendrobates to Anura. Change the UI for Unicode code point input to display the input field above the insertion point. Change the “Trim trailing blanks when saving” option in the “General” pane to perform trimming when you save instead of when you save but when you delay typing, and then move the option to the “Edit” pane. Enable to switch the editor split direction by right-clicking the editor split button in the navigation bar. Even if the split editor is not open, you can enable operations to switch the editor split direction. Delete the Integration Preferences pane and move its contents to the General pane. Even if the navigation bar is hidden, enable the “Select Previous/Next Outline Item” command. When the selection is moved, the selection count is updated in real time. Slide the line number area to scroll the editor. Previously, CotEditor scripts written using Unix scripts such as Ruby or Python were decoded using the user’s preferred file encoding set in the “Format” preference pane of normal documents, and now they are always interpreted as UTF-8. When the content of the document is empty, avoid displaying the “Edited” indicator in the close button of the document window, so the window can be closed without a confirmation dialog box. Update Swift, SVG and Ruby syntax styles. Update the syntax style of Shell scripts (thanks to ansimita!). Remove the toolbar button to toggle the visibility of the page guide. Delete the function to import the old-style syntax style definition file format used in CotEditor 1.x. Improve the tooltip of the toolbar icon to reflect the current document status. Optimize the calculation of the number of lines in the vertical text direction. Discontinuous layout is always enabled through the normal horizontal text direction. Update the build environment to Xcode 12.2 (Swift 5.3, macOS 11 SDK). Replace the DifferenceKit package with the native CollectionDifference. Update Yams from 3.0.1 to 4.0.0.
Fix Fix the jump button of theme URL. Fixed a problem in the sytnax style toolbar item: if the current style is deleted, the menu selection will be blank.
Known issues Some help content has not been updated yet. The document icon for Big Sur has not been updated.