Nowadays when a site functions in Chrome/Safari but not in Firefox, what are the common culprits?
Usage of experimental Web APIs? Specific CSS properties? Deprecated features still supported by Chrome/Safari for backward compatibility?
I ask because I'm wondering if it's possible for an extension/userjs to, if not polyfill, at least detect and warn users about attempts to use such features. Nowadays when a site doesn't appear to work correctly in Firefox I reopen it in Chrome, but this is a not-insignificant source of time-waste because about half of time I find either that the site is working as the developer intended, or that the site doesn't work in Chrome either. Having some overt indication (visible without having to open devtools) that unsupported browser features are being accessed could be very helpful here for reducing user uncertainty.
no, not at all. Pretty much anything Google does works across all browsers.
The most common culprit by far are local and regional sites. Local bank, doctor's office, random public website from the municipality, school homepage and so on. The few software developers they have on hand simply don't bother testing against Firefox any more so things just break and aren't fixed.
Usage of experimental Web APIs? Specific CSS properties? Deprecated features still supported by Chrome/Safari for backward compatibility?
I ask because I'm wondering if it's possible for an extension/userjs to, if not polyfill, at least detect and warn users about attempts to use such features. Nowadays when a site doesn't appear to work correctly in Firefox I reopen it in Chrome, but this is a not-insignificant source of time-waste because about half of time I find either that the site is working as the developer intended, or that the site doesn't work in Chrome either. Having some overt indication (visible without having to open devtools) that unsupported browser features are being accessed could be very helpful here for reducing user uncertainty.
Relatedly: I'm glad Firefox is planning to add support for IE's non-standard (but widely used ime) CSS zoom property: https://bugzilla.mozilla.org/show_bug.cgi?id=390936