CodeMirror

CodeMirror is a JavaScript component that provides a code editor in the browser. When a mode is available for the language you are coding in, it will color your code, and optionally help with indentation.

A rich programming API and a CSS theming system are available for customizing CodeMirror to fit your application, and extending it with new functionality.

Supported modes:

Usage demos:

Real-world uses:

jsbin.com (JS playground)
Light Table (experimental IDE)
Adobe Brackets (code editor)
Mergely (interactive diffing)
Google Apps Script
GitHub's Android app
Eloquent JavaScript (book)
Zen Coding (fast XML editing)
Paper.js (graphics scripting)
Go language tour
Codev (collaborative IDE)
Tributary (augmented editing)
Prose.io (github content editor)
WeScheme (learning tool)
WebGL playground
ql.io (http API query helper)
Elm language examples
The File Tree (collab editor)
JSHint (JS linter)
kl1p (paste service)
SQLFiddle (SQL playground)
Try Haxe (Haxe Playground)
CSSDeck (CSS showcase)
sketchPatch Livecodelab
NoTex (rST authoring)
More...

Getting the code

All of CodeMirror is released under a MIT-style license. To get it, you can download the latest release or the current development snapshot as zip files. To create a custom minified script file, you can use the compression API.

We use git for version control. The main repository can be fetched in this way:

git clone http://marijnhaverbeke.nl/git/codemirror

CodeMirror can also be found on GitHub at marijnh/CodeMirror. If you plan to hack on the code and contribute patches, the best way to do it is to create a GitHub fork, and send pull requests.

Documentation

The manual is your first stop for learning how to use this library. It starts with a quick explanation of how to use the editor, and then describes the API in detail.

For those who want to learn more about the code, there is a series of posts on CodeMirror on my blog, and the old overview of the editor internals. The source code itself is, for the most part, also very readable.

Support and bug reports

Community discussion, questions, and informal bug reporting is done on the CodeMirror Google group. There is a separate group, CodeMirror-announce, which is lower-volume, and is only used for major announcements—new versions and such. These will be cross-posted to both groups, so you don't need to subscribe to both.

Though bug reports through e-mail are responded to, the preferred way to report bugs is to use the GitHub issue tracker. Before reporting a bug, read these pointers. Also, the issue tracker is for bugs, not requests for help.

When none of these seem fitting, you can simply e-mail the maintainer directly.

Supported browsers

The following desktop browsers are able to run CodeMirror:

Firefox 3 or higher
Chrome, any version
Safari 5.2 or higher
Opera 9 or higher (with some key-handling problems on OS X)
Internet Explorer 8 or higher in standards mode
(Not quirks mode. But quasi-standards mode with a transitional doctype is also flaky. <!doctype html> is recommended.)
Internet Explorer 7 (standards mode) is usable, but buggy. It has a z-index bug that prevents CodeMirror from working properly.

I am not actively testing against every new browser release, and vendors have a habit of introducing bugs all the time, so I am relying on the community to tell me when something breaks. See here for information on how to contact me.

Mobile browsers mostly kind of work, but, because of limitations and their fundamentally different UI assumptions, show a lot of quirks that are hard to work around.

Commercial support

CodeMirror is developed and maintained by me, Marijn Haverbeke, in my own time. If your company is getting value out of CodeMirror, please consider purchasing a support contract.

You'll be funding further work on CodeMirror.
You ensure that you get a quick response when you have a problem, even when I am otherwise busy.

CodeMirror support contracts exist in two forms—basic at €100 per month, and premium at €500 per month. Contact me for further information.

Download the latest release

Support CodeMirror

Donate (Paypal, bank, or Gittip)
Purchase commercial support

Reading material

Releases

20-11-2012: Version 3.0:

New major version. Only partially backwards-compatible. See the upgrading guide for more information. Changes since release candidate 2:

Rewritten VIM mode.
Fix a few minor scrolling and sizing issues.
Work around Safari segfault when dragging.
Full list of patches.

20-11-2012: Version 3.0, release candidate 2:

New mode: HTTP.
Improved handling of selection anchor position.
Improve IE performance on longer lines.
Reduce gutter glitches during horiz. scrolling.
Add addKeyMap and removeKeyMap methods.
Rewrite formatting and closetag add-ons.
Full list of patches.

20-11-2012: Version 2.36:

New mode: Z80 assembly.
New theme: Twilight.
Add command-line compression helper.
Make scrollIntoView public.
Add defaultTextHeight method.
Various extensions to the vim keymap.
Make PHP mode build on mixed HTML mode.
Add comment-continuing add-on.
Full list of patches.

20-11-2012: Version 3.0, release candidate 1:

New theme: Solarized.
Introduce addLineClass and removeLineClass, drop setLineClass.
Add a lot of new options for marked text (read-only, atomic, collapsed, widget replacement).
Remove the old code folding interface in favour of these new ranges.
Add isClean/markClean methods.
Remove compoundChange method, use better undo-event-combining heuristic.
Improve scrolling performance smoothness.
Full list of patches.

22-10-2012: Version 2.35:

New (sub) mode: TypeScript.
Don't overwrite (insert key) when pasting.
Fix several bugs in markText/undo interaction.
Better indentation of JavaScript code without semicolons.
Add defineInitHook function.
Full list of patches.

22-10-2012: Version 3.0, beta 2:

Fix page-based coordinate computation.
Fix firing of gutterClick event.
Add cursorHeight option.
Fix bi-directional text regression.
Add viewportMargin option.
Directly handle mousewheel events (again, hopefully better).
Make vertical cursor movement more robust (through widgets, big line gaps).
Add flattenSpans option.
Many optimizations. Poor responsiveness should be fixed.
Initialization in hidden state works again.
Full list of patches.

19-09-2012: Version 2.34:

New mode: Common Lisp.
Fix right-click select-all on most browsers.
Change the way highlighting happens:
Saves memory and CPU cycles.
compareStates is no longer needed.
onHighlightComplete no longer works.
Integrate mode (Markdown, XQuery, CSS, sTex) tests in central testsuite.
Add a CodeMirror.version property.
More robust handling of nested modes in formatting and closetag plug-ins.
Un/redo now preserves marked text and bookmarks.
Full list of patches.

19-09-2012: Version 3.0, beta 1:

Bi-directional text support.
More powerful gutter model.
Support for arbitrary text/widget height.
In-line widgets.
Generalized event handling.

23-08-2012: Version 2.33:

New mode: Sieve.
New getViewPort and onViewportChange API.
Configurable cursor blink rate.
Make binding a key to false disabling handling (again).
Show non-printing characters as red dots.
More tweaks to the scrolling model.
Expanded testsuite. Basic linter added.
Remove most uses of innerHTML. Remove CodeMirror.htmlEscape.
Full list of patches.

23-07-2012: Version 2.32:

Emergency fix for a bug where an editor with line wrapping on IE will break when there is no scrollbar.

20-07-2012: Version 2.31:

New modes: OCaml, Haxe, and VB.NET.
Several fixes to the new scrolling model.
Add a setSize method for programmatic resizing.
Add getHistory and setHistory methods.
Allow custom line separator string in getValue and getRange.
Support double- and triple-click drag, double-clicking whitespace.
And more... (all patches)

22-06-2012: Version 2.3:

New scrollbar implementation. Should flicker less. Changes DOM structure of the editor.
New theme: vibrant-ink.
Many extensions to the VIM keymap (including text objects).
Add mode-multiplexing utility script.
Fix bug where right-click paste works in read-only mode.
Add a getScrollInfo method.
Lots of other fixes.

23-05-2012: Version 2.25:

New mode: Erlang.
Remove xmlpure mode (use xml.js).
Fix line-wrapping in Opera.
Fix X Windows middle-click paste in Chrome.
Fix bug that broke pasting of huge documents.
Fix backspace and tab key repeat in Opera.

Older releases...

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