mapbox/pixelmatch

Health v2 · maintenance only

Adoption not part of the score

6931 stars · 323 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

A tiny, dependency-free JavaScript library for pixel-level image comparison, originally built for comparing screenshots in tests. It works on raw typed arrays in both Node and browsers, with anti-aliased pixel detection and perceptual (OKLab) color difference metrics.

Use cases

• compare screenshots in automated tests
• generate visual diff images of two images
• detect pixel differences between PNG images in Node
• visual regression testing for web UIs
• compare image data in the browser
• ignore anti-aliased pixels when diffing images

When to choose

• you need a fast, zero-dependency pixel diff that works on raw image data
• you want perceptually accurate comparison that handles anti-aliasing
• you need it to run in both Node and browsers
• you want a diff image highlighting changed pixels

When to avoid

• you need to decode/encode image files yourself (it only compares raw pixel arrays)
• you need image resizing or dimension mismatch handling
• you need a full visual regression framework with reporting and baselines

Facets

library · maturity stable

image-processing testing image-processing testing developer-tools browser pixel-diff visual-regression screenshot-testing zero-dependency nodejs javascript

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