User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0

Steps to reproduce:

Firefox 91.0 (in the troubleshoot mode), Ubuntu 20.04 LTS.
Open the developer tools and reload a page without closing a tab many times (more than 50 times, e.g. during front end development). From my observation there is no difference between reloading a certain page or switching between different (within a certain tab)

Actual results:

Memory grabbing happens. Each refresh increases memory usage without any limits, memory releasing happens only after closing a tab.
Please see 'pid 20496' in the attached file. In this case the main process is eating 1.3 GB eats and the tab is eating 793 MB. After reopening the tab the main process is eating 284 MB and the tab is eating 200 MB.
During many hours development I'm getting sometimes 1.5-2GB for a problematic tab and the same for a main process.

Expected results:

A tab with opened developer tools shouldn't unlimited grabbing memory

The Bugbug bot thinks this bug should belong to the 'DevTools::General' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Additional details - an active tab in the developers tools is Inspector, but I'm not sure it doesn't happen when another is active

Thanks for the report. The leak is on reload is already known and should be significantly reduced after https://bugzilla.mozilla.org/show_bug.cgi?id=1702715 lands (probably this week).

Do you have a test page, or a specific scenario to provide? Otherwise we may close this as duplicate of Bug 1682212

Thank you for the update. I don't have a specific scenario, as I've mentioned it happens for any website.