CodeMirror
CodeMirror is a free, MIT-licensed code editor component for websites.
What CodeMirror is
CodeMirror is a free, MIT-licensed code editor component for websites. Developers get an API for extending the editor and npm packages under the @codemirror scope. Editing features include syntax highlighting, line numbers, autocompletion, code folding, search and replace, linting, and multiple selections. Extensions can add capabilities such as highlighting and undo history, while language-server support is available. Parser packages are listed for JavaScript, Python, Rust, SQL, HTML, CSS, and JSON. The site says CodeMirror works with screen readers and keyboard-only users and uses native selection and editing features on phones. A reference-manual option allows a Content Security Policy nonce for editor style sheets. Commercial use is permitted under the MIT license. The listed plan costs nothing. Questions go to the forum and bug reports to the issue tracker.
Good
- MIT license permits commercial use
- Extensible API and npm package structure
- Includes autocomplete, folding, and linting
- Works with screen readers and keyboard-only users
- Supports multiple language parsers
Watch out
- No current support price is listed
- It is a web component, not a standalone desktop editor
Who it suits
It suits web developers embedding an editor component who need extensibility and common editing features. It also fits projects requiring accessibility and commercial-use permission.
Verdict
CodeMirror provides a broad editing foundation for web applications with an extensible package model. Its free MIT license and accessibility features make it practical when those requirements match.
Plans and prices
From CodeMirror's own pricing page, checked 11 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| CodeMirror (MIT open-source library) | Free | Web code editor component · MIT license · commercial use is permitted |
The facts
Each one read from CodeMirror's own pages, with the date it was checked.
What it does
- Accessibility and mobile
- The site says CodeMirror works with screen readers and keyboard-only users, and uses native selection and editing features on phones.checked 11 Oct 2026
- Editing features
- Features include syntax highlighting, line numbers, autocompletion, code folding, search and replace, linting, and multiple selections.checked 11 Oct 2026
- Extensibility
- The reference manual describes CodeMirror as a set of npm packages under the @codemirror scope, with features such as highlighting and undo history added through extensions.checked 11 Oct 2026
- Extension support
- Yeschecked 20 Sep 2026
- Language server support
- Yeschecked 20 Sep 2026
- Language support
- The site lists parser packages for languages including JavaScript, Python, Rust, SQL, HTML, CSS, and JSON.checked 11 Oct 2026
- License and commercial use
- The site describes CodeMirror as MIT-licensed and says commercial users are socially, but not legally, expected to help fund maintenance.checked 11 Oct 2026
- Security-related capability
- The reference manual documents an option to provide a Content Security Policy nonce for editor style sheets.checked 11 Oct 2026
- Support
- The site directs questions to its forum and bug reports to its issue tracker; it does not list support response times or a current support price.checked 11 Oct 2026
- What it does
- CodeMirror is a code editor component for websites, with an API for extending it.checked 11 Oct 2026
The company
- Maker
- The site says CodeMirror is developed on code.haverbeke.berlin and identifies Marijn Haverbeke as its maintainer on an older project page.checked 11 Oct 2026
Where it runs
- Supported platforms
- webchecked 20 Sep 2026
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