How to Clear Cache and Cookies in Firefox (2025 Update)

Firefox can be configured to use only RAM as cache storage. Configuration files, bookmarks, extensions etc. will be written to drive as usual.

Memory Cache is a project that allows you to save a webpage while you're browsing in Firefox as a PDF, and save it to a synchronized folder.

To get rid of lagging and video stuttering in Firefox type about:config in the Firefox address bar and change the following preferences.

The answer as to why it's like that is because internally disk cache includes by default memory cache. The result is a slightly irrelevant about:cache page.

The Firefox cache temporarily stores parts of websites you visit. Learn how to clear it to fix issues with how websites work or look.

Type about:config into the address bar, press Enter, accept the warning, scroll down the alphabetical list to browser.cache.disk.smart_size.enabled and double ...

I want to increase firefox's memory cache. From the knowledge base, this seems to be the value that should be changed.

Assuming that there is memory to spare, placing Firefox's cache or complete profile to RAM offers significant advantages.

there are modifications you can make to about:config / user.js to disable the disk cache (if you choose), and use more memory (if you choose) ...

Just built a brand new PC, and went surfing for a couple of days when I noticed Firefox' cache was already up to 1GB in size.