A simple google-esque polyline
implementation in Javascript. Compatible with nodejs (npm install polyline and the browser (copy src/polyline.js)).
Encodes/decodes into lat/lng coordinate pairs. Flip the pairs to be compatible with GeoJSON.
npm install polyline
var polyline = require('polyline');
// returns an array of lat, lon pairs
polyline.decode('_p~iF~ps|U_ulLnnqC_mqNvxq`@')
// returns a string-encoded polyline
polyline.encode([[38.5, -120.2], [40.7, -120.95], [43.252, -126.453]]);