"about:performance" does not show any pages or add-ons being memory hogs. The memory use per page that it shows is surprisingly small, and the total comes to <

"about:performance" does not show any pages or add-ons being memory hogs. The memory use per page that it shows is surprisingly small, and the total comes to < 1GB. And I see the real memory usage grown, eventually to crashing size, even when I'm just reading around HN, clicking many article headings and comments but remaining within the HN text-only site. I agree it's probably made worse caused by specific sites, but I haven't been able to figure out which ones, or perhaps it's wide range of them, which defeats browsing in general. However, I now avoid Telegram Web, because that does consistently crash Firefox for me eventually (I've seen reported memory use grow to 67GB when TW was open, about three times). Whatever it is, it doesn't look like site JavaScript holding data in large JavaScript objects or DOM trees, because minimizing memory use with "about:memory" reduces the size to workable levels without any other observable effect on open pages. So I'm inclined to think of the Firefox as having a severe reclaimable-but-not-reclaimed memory leak or cache problem of some kind, that is outside the world of JavaScript data.