# pa7/heatmap.js

🔥 JavaScript Library for HTML5 canvas based heatmaps

Repository: https://github.com/pa7/heatmap.js
Canonical: https://ross.abutalabs.com/products/heatmapjs
Homepage: https://www.patrick-wied.at/static/heatmapjs/
Language: JavaScript
License: MIT
License Family: permissive
Topics: heatmaps, data-visualization, heat-maps, dataviz, leaflet, google-maps, leaflet-plugins, openlayers, angularjs, canvas, density-visualization, heatmap, javascript, visualization, interactive
Last push: 2023-10-31T03:05:44+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 5613, "days_push": 1037, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 6379, forks 1318 (observed 2026-08-28T04:09:42.942722+00:00)

## What it is
heatmap.js is a lightweight JavaScript library for rendering dynamic heatmaps on HTML5 canvas in the browser. It supports plugins for map libraries like Leaflet, Google Maps, and OpenLayers, and can handle 40k+ datapoints.

## Use cases
- visualize user click behavior on a webpage as a heatmap
- plot thousands of geo events on a Leaflet map as a density heatmap
- add an interactive heatmap overlay to Google Maps
- render point density visualizations on HTML5 canvas
- create a heatmap legend with gradient colors and opacity controls

## When to choose
- you need client-side heatmap rendering in the browser with a tiny footprint
- you want heatmap overlays on Leaflet, Google Maps, or OpenLayers
- you need a simple, well-documented canvas-based density visualization

## When to avoid
- you need server-side or non-browser heatmap rendering
- you need actively developed features or timely PR merges
- you need WebGL-scale performance for millions of points

## Facets
- artifact type: library
- maturity: maintenance
- function: data-visualization, charts
- domain: data-visualization, web-development
- platform: browser
- tags: heatmap, canvas, leaflet, google-maps, openlayers, density-visualization, gis, maps, javascript

## Member repositories
- pa7/heatmap.js (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:42.942722+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 2026-08-29T17:45:09.838472+00:00, confidence not recorded.
  - readme: https://github.com/pa7/heatmap.js (fetched 2026-08-28T04:09:42.942722+00:00, sha 93bf8e679b51)
  - homepage: https://www.patrick-wied.at/static/heatmapjs/ (fetched 2026-08-29T08:42:24.677397+00:00, sha 622a3d2b8931)
  - site_page: https://www.patrick-wied.at/static/heatmapjs/docs.html (fetched 2026-08-29T08:42:24.709967+00:00, sha 22df88d505c8)
  - site_page: https://www.patrick-wied.at/static/heatmapjs/frequently-asked-questions.html (fetched 2026-08-29T08:42:24.762512+00:00, sha 896883fd7d5e)
- Data as of 2026-08-30T08:39:29.467469+00:00.