CodeMirror
A legacy JavaScript code editor for web pages, with over 100 language modes.codemirror/codemirror5
- Stars
- 27.2k
- Forks
- 4.9k
- Licence
- MIT
- Language
- JavaScript
- Last update
- 7 months ago
- Type
- Library
This repository is archived and no longer maintained.
What it is
CodeMirror 5 is a code editor written in JavaScript that runs inside a web browser. It provides syntax highlighting for more than 100 programming languages, plus add-ons for more advanced editing features. Developers add it to their own web applications to give users a code-editing box. The project is archived, and its README points to CodeMirror 6 as the more actively maintained successor.
- Embed a syntax-highlighted code editor in a web page
- Choose from over 100 language modes for highlighting
- Customize the editor's look with its CSS theming system
- Extend editing behavior using its programming API and add-ons
Great for
- Developers maintaining an existing site or app that already uses CodeMirror 5
- Teams that need a browser code editor with many language modes and a theming system
- Developers who want to read the legacy API while migrating to CodeMirror 6
Not ideal for
- New projects: the README says CodeMirror 6 is more mobile-friendly, more accessible and actively maintained, and this repository is archived
- Mobile-first apps, since the README describes CodeMirror 6 as the more mobile-friendly option
- Non-developers looking for a ready-made text editor app, since this is a library to embed in other software
How to get it
- 1
Install with a package manager
You'll need: Node.js (at least version 6, per the README) · npm
Install the library from npm
npm install codemirror@5 - 2
Run it
- Install the package with npm install codemirror@5
- Include the library in your web page or bundle
- Create an editor instance in JavaScript and attach it to a page element
- 3
Get the most out of it
- Read the manual at codemirror.net/5/doc/manual.html for the full API
- Use the language modes you need rather than loading all of them
- Apply CSS themes to match your application's look
- Ask questions on the discussion forum at discuss.codemirror.net
Downloads
Strengths
- Large language support, with over 100 language modes according to the README
- Rich programming API and CSS theming for customization
- Long history and a large community, with 27,198 GitHub stars
Trade-offs
- Archived and no longer the actively maintained version, per the README's note about CodeMirror 6
- The README says cloning the repo will not work for installing without the build step, so the npm package is the intended route
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| codemirror5 (this) | 27.2k | Library | intermediate | 7 months ago | Developers maintaining an existing site or app that already uses CodeMirror 5 |
| monaco-editor | 46.9k | Library | intermediate | 6 days ago | Web developers adding a code editing box to a browser app |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.