// the find
pa7/heatmap.js
🔥 JavaScript Library for HTML5 canvas based heatmaps
heatmap.js renders density heatmaps on HTML5 canvas with plugins for Google Maps, Leaflet, and OpenLayers. It's for anyone who needs to visualize point-density data — click maps, sensor readings, geographic concentrations — without pulling in a heavy charting framework. The core API is small and the map integrations are the main selling point.
Plugin architecture is genuinely clean — the core renderer is decoupled from map layers, so Leaflet and Google Maps adapters are thin wrappers rather than forks. Canvas 2D renderer handles large datasets acceptably via Gaussian blur compositing, which is the right approach for smooth-looking heatmaps. Zero runtime dependencies in the core build. The included examples cover the common cases (mousemove tracking, geo overlays, SVG areas) with working code you can actually run.
Last real activity was 2023 and the README still recommends Bower, which tells you how long the project has been in maintenance-only mode — you're adopting something nobody is actively improving. Tests are entirely visual (open an HTML file and look at it), so there's no way to know if a change broke something without eyeballing it. No TypeScript types in the package, which matters if you're in a typed codebase — you'll be writing your own. Performance degrades noticeably with datasets above ~50k points because it's doing per-point Gaussian blur on the CPU; if you have dense data you'll hit the ceiling fast.