pixelmatch
Metrics as of , from the GitHub or GitLab API of each repository. Refreshed monthly.
What pixelmatch is
pixelmatch is a JavaScript library for pixel-level image comparison, first written to compare screenshots in tests. It detects anti-aliased pixels and measures colour difference with perceptual metrics based on the OKLab colour space. The library has no dependencies and operates directly on typed arrays of raw image data. It runs in Node.js and in browsers. A call returns the count of mismatched pixels and can write a diff image. Options set the matching threshold, diff colours and a transparent diff mask. A windowSize option reports the highest count of differing pixels within any N by N window, which filters scattered noise. A bundled command-line binary compares PNG files.
Written from the project's README, read .
- Category
- Visual regression
- License
- ISC
- Language
- JavaScript
- Changelog
- Releases on GitHub
Repository metrics
Status
activeLast commit within 90 days of the fetch date.Computed from the last commit date and the archive flag on the fetch date. See the status rules.
Alternatives
Listed visual regression tools, same primary language first, then by GitHub stars. Each line gives one fact from the tool's documentation where it differs from pixelmatch's, with its source.
BackstopJS: Test authoring format: JSON or JavaScript config file (backstop.json) with scenarios; onBefore and onReady scripts. source: README
jest-image-snapshot: Test authoring format: Code (Jest matcher toMatchImageSnapshot on PNG image buffers). source: README
Loki: Test authoring format: Existing Storybook stories, captured and compared by the loki CLI. source: Docs: Getting started
Lost Pixel: Test authoring format: Config file lostpixel.config.js or lostpixel.config.ts in the project repo. source: Docs: Project Configuration
reg-suit: Test authoring format: Image files in a configured directory (actualDir); settings in regconfig.json. source: README
Testplane: Test authoring format: Code (describe/it callbacks that receive a browser client). source: Docs: Writing Tests
Visual Regression Tracker: Test authoring format: Code: image assertions added to existing tests through SDKs (JS, Java, Python, .NET) or the REST API. source: README
Comparisons
How to install
npm install pixelmatchQuestions
Is pixelmatch open source?
Yes. pixelmatch is released under ISC, an OSI-approved license, as reported by the GitHub API on 2026-09-22.
Is pixelmatch maintained?
On 2026-09-22, the last commit to the default branch was on 2026-09-15, so the listed status is active. Rule: Last commit within 90 days of the fetch date.
How many GitHub stars does pixelmatch have?
6,957 stars on 2026-09-22, from the GitHub API. The number is refreshed at each monthly update.
What language is pixelmatch written in?
The repository's primary language, as reported by the GitHub API, is JavaScript.
How do I install pixelmatch?
The README gives this command: npm install pixelmatch
Sources
- GitHub REST API: repository, read
- GitHub REST API: commits, read
- GitHub REST API: latest release, read
- GitHub REST API: contributors, read
- README, read