Chart.xkcd is described as 'Chart library that plots “sketchy” or “hand-drawn” styled charts' and is an app in the Development category. There are three alternatives to Chart.xkcd for Self-Hosted solutions and React. The best alternative is Rough.js, which is both free and Open Source. Other great apps like Chart.xkcd are Rough Charts (Free, Open Source) and roughViz (Free, Open Source).
Rough.js is a light weight (~8k), Canvas based library that lets you draw in a sketchy, hand-drawn-like, style. The library defines primitives to draw lines, curves, arcs, polygons, circles, and ellipses. It also supports drawing SVG paths.