Browser.cache.memory.capacity !!exclusive!! Jun 2026

Setting the value to effectively disables the memory cache. This is rarely recommended for general use, as it forces the browser to pull every single asset from the slower disk cache or the internet, significantly degrading performance. 3. Manual Allocation (Specific Integer)

browser.cache.memory.capacity is a powerful configuration tool that gives users granular control over how their browser utilizes system memory. While it was a critical tweak in older versions of browsers, modern automatic memory management has made manual adjustment largely unnecessary. Incorrect configuration (such as setting it to 0 ) can severely degrade browser performance. Therefore, modification is recommended only for advanced users with specific hardware constraints or performance goals. Browser.cache.memory.capacity

Increasing this value can speed up page navigation (especially the Back/Forward buttons) by keeping recently visited pages in RAM instead of reloading them from the slower disk or the internet. How to Configure It Setting the value to effectively disables the memory cache

You are running Firefox on a legacy system with 4GB of RAM. You also run a Virtual Machine, Adobe Photoshop, or a local development server (Docker, Node). Every megabyte matters. Manual Allocation (Specific Integer) browser

If it doesn’t exist, you can as a new integer preference.

Here is a cheat sheet for different user profiles:

Replace the static numeric pref with a in browser settings (under Performance or Privacy & Security).