# rsmbl/Resemble.js

Image analysis and comparison

Repository: https://github.com/rsmbl/Resemble.js
Canonical: https://ross.abutalabs.com/products/resemblejs
Homepage: http://rsmbl.github.io/Resemble.js/
Language: JavaScript
License: MIT
License Family: permissive
Last push: 2024-02-06T21:57:14+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4941, "days_push": 939, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4612, forks 419 (observed 2026-08-28T04:08:55.042666+00:00)

## What it is
Resemble.js is a JavaScript library for analyzing and comparing images using HTML5 canvas, producing pixel-level diff images and analysis data. It works in the browser and in Node.js (via node-canvas), and was originally built for visual regression testing tools like PhantomCSS.

## Use cases
- compare two images and generate a visual diff
- visual regression testing of screenshots
- analyze image brightness and color statistics
- ignore antialiasing or colors when diffing screenshots
- detect differences between UI screenshots in e2e tests

## When to choose
- you need pixel-level image comparison in JavaScript, in browser or Node.js
- you are building visual regression testing and need to ignore antialiasing noise
- you want basic image analysis (brightness, RGBA stats) without heavy dependencies

## When to avoid
- you need actively maintained software with fast issue turnaround (it is in low-maintenance mode)
- you need high-performance or large-scale image processing (native libraries like OpenCV or ImageMagick are better)
- you need perceptual or semantic image similarity rather than pixel diffs

## Facets
- artifact type: library
- maturity: maintenance
- function: image-processing, testing
- domain: image-processing, testing, web-development
- platform: browser, cross-platform
- tags: visual-regression, image-diff, html5-canvas, screenshot-comparison, nodejs

## Member repositories
- rsmbl/Resemble.js (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:55.042666+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:19:42.830599+00:00, confidence not recorded.
  - readme: https://github.com/rsmbl/Resemble.js (fetched 2026-08-28T04:08:55.042666+00:00, sha 2037426471f4)
  - homepage: http://rsmbl.github.io/Resemble.js/ (fetched 2026-08-29T09:04:47.431784+00:00, sha 56c9cbe89093)
- Data as of 2026-08-30T08:39:29.467469+00:00.