Finally, Firefox makes it easier to check how much memory it is using

Firefox and Chrome are well-known memory hogs because they use a multi-process architecture. Understanding how Firefox consumes memory shouldn’t be difficult for the average user. This is where the about:memory reports come in, revealing detailed data—but the tree structure they display can be hard to understand.

Mozilla is working to make it easier for users to see how much memory Firefox is using via about:memory. In fact, this improvement can already be seen in Nightly, where Firefox now displays memory usage when clicking the Measure option under memory reports on the about:memory page. At the top, it shows the total resident memory used, with the process index on the right and explicit memory locations listed below.

Additionally, Mozilla is addressing memory issues with a manual tab unloading feature.

If you notice Firefox is using too much RAM, ensure you are using the latest version of Firefox with a minimal number of extensions. Also, make sure hardware acceleration is turned on in Settings for Firefox. Try refreshing Firefox or adding more RAM to your computer.