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:

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, Gittip, or Flattr)
Purchase commercial support

Reading material

Releases

20-05-2013: Version 3.13:

New modes: COBOL and HAML.
New options: cursorScrollMargin and coverGutterNextToScrollbar.
New addon: commenting.
More features added to the Vim keymap.
Full list of patches.

19-04-2013: Version 3.12:

New mode: GNU assembler.
New options: maxHighlightLength and historyEventDelay.
Added addToHistory option for markText.
Various fixes to JavaScript tokenization and indentation corner cases.
Further improvements to the vim mode.
Full list of patches.

20-03-2013: Version 3.11:

Removed code: collapserange, formatting, and simple-hint addons. plsql and mysql modes (use sql mode).
Moved code: the range-finding functions for folding now have their own files.
Changed interface: the continuecomment addon now exposes an option, rather than a command.
New modes: SCSS, Tcl, LiveScript, and mIRC.
New addons: placeholder, HTML completion.
New methods: hasFocus, defaultCharWidth.
New events: beforeCursorEnter, renderLine.
Many improvements to the show-hint completion dialog addon.
Tweak behavior of by-word cursor motion.
Further improvements to the vim mode.
Full list of patches.

21-02-2013: Version 3.1:

Incompatible: key handlers may now return, rather than throw CodeMirror.Pass to signal they didn't handle the key.
Make documents a first-class construct, support split views and subviews.
Add a new module for showing completion hints. Deprecate simple-hint.js.
Extend htmlmixed mode to allow custom handling of script types.
Support an insertLeft option to setBookmark.
Add an eachLine method to iterate over a document.
New addon modules: selection marking, linting, and automatic bracket closing.
Add "beforeChange" and "beforeSelectionChange" events.
Add "hide" and "unhide" events to marked ranges.
Fix coordsChar's interpretation of its argument to match the documentation.
New modes: Turtle and Q.
Further improvements to the vim mode.
Full list of patches.

25-01-2013: Version 3.02:

Single-bugfix release. Fixes a problem that prevents CodeMirror instances from being garbage-collected after they become unused.

21-01-2013: Version 3.01:

Move all add-ons into an organized directory structure under /addon. You might have to adjust your paths.
New modes: D, Sass, APL, SQL (configurable), and Asterisk.
Several bugfixes in right-to-left text support.
Add rtlMoveVisually option.
Improvements to vim keymap.
Add built-in (lightweight) overlay mode support.
Support showIfHidden option for line widgets.
Add simple Python hinter.
Bring back the fixedGutter option.
Full list of patches.

21-01-2013: Version 2.38:

Integrate some bugfixes, enhancements to the vim keymap, and new modes (D, Sass, APL) from the v3 branch.

20-12-2012: Version 2.37:

New mode: SQL (will replace plsql and mysql modes).
Further work on the new VIM mode.
Fix Cmd/Ctrl keys on recent Operas on OS X.
Full list of patches.

10-12-2012: 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.

Older releases...

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