I have made a website in simple HTML and CSS (no JS).
I hope it would be compatible with as many browsers as possible.
Is there a free and open source solution that can test and reveal the oldest version of each browser compatible with my site? I want to be able to say something like: This site is compatible with FF v60, Chromium v50, Safari vxx, etc.
Or make a compatibility table so users can know that this was tested.


Hmm, I have a blink and a gecko browser on desktop and mobile, and open the site on both to check how it’s being displayed :S
I hear a lot of people complaining about sites breaking on Firefox, but I never experienced that, only on secure forks that removed canvas, webgl and webgpu.
I have a few static sites as well and I use JS. The only thing I noticed changing, that can push elements weirdly, is scroll bars, buttons, the default audio player… but you can edit those with css to look similar on both browsers.