# mourner/simplify-js

High-performance JavaScript polyline simplification library

Repository: https://github.com/mourner/simplify-js
Canonical: https://ross.abutalabs.com/products/simplify-js
Homepage: http://mourner.github.io/simplify-js
Language: JavaScript
License: BSD-2-Clause
License Family: permissive
Last push: 2022-11-14T20:13:23+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": 5325, "days_push": 1388, "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 2393, forks 207 (observed 2026-08-28T04:06:43.416520+00:00)

## What it is
Simplify.js is a tiny, high-performance JavaScript library for 2D/3D polyline simplification, extracted from Leaflet. It combines the Douglas-Peucker and Radial Distance algorithms to dramatically reduce the number of points in a polyline while retaining its shape.

## Use cases
- simplify map routes before rendering on canvas or svg
- reduce points in a 70k-point line chart for faster rendering
- downsample GPS tracks to shrink data size
- smooth noisy polyline data while keeping its shape
- speed up geometric processing of large coordinate arrays

## When to choose
- you need fast, dependency-free polyline/point reduction in JavaScript in the browser or Node
- you render large paths (maps, charts) and want to cut visual noise and boost performance
- you want a tiny, well-tested algorithm extracted from Leaflet

## When to avoid
- you need polygon topology-aware simplification (e.g. mapnik/topo-style shared-edge simplification)
- you work in another language and prefer a native port (ports exist for Python, Rust, Go, etc.)
- you need geodesic-aware simplification that accounts for projection distortion

## Facets
- artifact type: library
- maturity: stable
- function: math, graphics, data-visualization
- domain: graphics, data-visualization
- platform: browser, cross-platform
- tags: polyline-simplification, geometry, douglas-peucker, maps, canvas, svg, algorithms, nodejs

## Member repositories
- mourner/simplify-js (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:43.416520+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 2026-08-30T02:34:26.301281+00:00, confidence not recorded.
  - readme: https://github.com/mourner/simplify-js (fetched 2026-08-28T04:06:43.416520+00:00, sha 815675ba9243)
  - homepage: http://mourner.github.io/simplify-js (fetched 2026-08-29T10:15:21.690403+00:00, sha 5a563e6df296)
  - registry_npm: https://registry.npmjs.org/simplify-js (fetched 2026-08-29T10:15:21.694066+00:00, sha 09e0edf3168f)
- Data as of 2026-08-30T08:39:29.467469+00:00.