This repo demonstrates some browser bugs that tend to affect drawing web apps the most. Status should be fairly up-to-date.

Visit here for easy viewing of demos:

Not Fixed


Date Live Demo Summary Effects Issue Link
2021-02-15 View In an iframe, when using a stylus, PointerEvent.pointerId is inconsistent. Drawing applications can't reliably run in iframes. I.e. Kleki/Klecks can't be easily embedded via iframe. Chromium Ticket (reported 2021-02-15)
2022-04-28 View CanvasRenderingContext2D deletes parts of image after switching tabs. With certain hardware, drawing apps or image editing apps aren't reliable, as image data gets corrupted when switching tabs. I.e. Kleki/Klecks users lose progress. Chromium Ticket (reported 2022-03-24)
2022-10-19 View Context2d arc() fill() draws jagged circles on MacOS M1. Applications relying on the canvas arc method achieve bad quality circles. I.e. the pen tool in Kleki/Klecks looks much worse. Chromium Ticket (reported 2022-10-23)
2023-05-06 canvas.context('webgl') fails on Chrome OS on some pages (not on all devices) Features relying on WebGL do not work (filters in Kleki/Klecks) Chromium Ticket (reported 2023-05-06)


Date Live Demo Summary Effects Issue Link
2023-04-30 View Canvas putImageData draws onto wrong canvas. If you duplicate canvases, the putImageData method becomes unreliable. I.e. it breaks the paint bucket in Kleki/Klecks without a special workaround. WebKit Bugzilla Ticket (reported on 2023-04-30)


Date Live Demo Summary Effects Issue Link
2022-03-08 View PointerEvent.buttons attribute is inconsistent when using a stylus. Drawing applications break, unless they handle Firefox differently (not trust the button attribute). Bugzilla Ticket (reported 2022-03-08)