It's free, open source, and no watermark - so QuickChart compares favorably in that regard! In terms of functionality, ChartURL is also built on Chart.js, so c

It's free, open source, and no watermark - so QuickChart compares favorably in that regard! In terms of functionality, ChartURL is also built on Chart.js, so charting capabilities should be roughly equivalent. They've added the nice feature of being able to save your charts to a short URL.