...most chart libs use SVG. Beside Highcharts (not open source) I have yet to see a SVG based charting lib that is fast and lightweight. d3.js and chart libs based on d3.js (like plot.ly) are very heavy weigth in comparision (= more than 100KB minified JS code; plot.ly is 1.05MB huge: https://github.com/plotly/plotly.js/blob/master/dist/plotly.... )

SVG wasn't supported until Android 4 and only Internet Explorer/Edge is really optimized for SVG (thanks to their VML investment). On the other hand Chrome, Safari and Firefox render Canvas much faster. (only relevant if you want to render thousends of objects on a battery powered device)