How to Override Firefox’s Automatic Performance Settings

Firefox picks its own performance values based on your hardware, which is handy until you want a specific setting to stay put. Clearing the recommended bundle hands those controls back to you.

Open Settings, search for performance, and uncheck Use recommended performance settings. Then set hardware acceleration and the content process limit, and reopen the page once to confirm your choices stuck.

In this guide, I have covered:

Why Firefox selects performance settings automatically

You go looking for a specific performance control and find one checkbox doing all the work. Use recommended performance settings bundles a couple of choices together, and Firefox says it picks those values from your hardware and operating system. That is why they can change on their own after an update.

Clearing the bundle does not switch off any Firefox performance feature. It lays the individual controls out so you can keep or replace what Firefox chose. The Firefox performance settings page on Mozilla Support describes the same option.

Clear the recommended performance setting

Performance sits under Tabs and browsing in the current layout, not General. The search box at the top of Settings gets you there fastest.

1. Open the menu.
2. Choose Settings.
3. Click Find in Settings at the top of the page.
4. Type performance.
5. Open the Performance section in the results.
6. Clear the Use recommended performance settings checkbox.

The checkbox should now be empty, with Use hardware acceleration when available and Content process limit ready for you to change.

If an older guide sends you to General, use Find in Settings instead. Performance lives inside Tabs and browsing now.

Override hardware acceleration

Heavy scrolling or stuttering video is your cue to touch this control. With the recommended bundle off, you decide whether Firefox uses hardware acceleration instead of accepting its choice.

1. Click the hamburger menu and choose Settings, then select General from the left sidebar.
2. Scroll to the Performance section.
3. If "Use recommended performance settings" is checked, uncheck it to expose the manual options.
4. Uncheck "Use hardware acceleration when available".
5. Restart Firefox from the hamburger menu so the change takes effect.

You’ll know it worked when you return to Performance and Use hardware acceleration when available shows the state you picked.

Set the content process limit

Content processes keep tabs separate, and more of them can keep a crowded window responsive. They also eat memory. Firefox says extra processes help when you run many tabs at once, so this setting is a straight trade between speed and RAM.

1. Open Content process limit.
2. Choose the value that matches your memory and your usual tab count.
3. Check that the control shows the value you selected.

If the current number already suits your machine, leave it alone. What matters is that Use recommended performance settings stays clear.

Verify that the override stayed active

Reopening Settings takes ten seconds and proves the override survived.

1. Close the Settings page.
2. Open the menu.
3. Choose Settings.
4. Click Find in Settings.
5. Type performance.
6. Open Performance in the results.
7. Confirm that Use recommended performance settings is still clear.
8. Confirm that Content process limit shows your selected value.

Both checks pass? Firefox is now doing what you told it.

If the controls are missing or the change does not stick

A search that returns nothing usually means the browser is behind. Our guide to downloading and updating Firefox to the latest version covers that first.

1. Close the Settings page.
2. Open the menu.
3. Choose Settings.
4. Click Find in Settings.
5. Type performance.
6. Open Performance under Tabs and browsing.
7. Clear Use recommended performance settings again.

TIP: Use the normal Settings controls for this task. Mozilla warns that changing preferences in about:config can affect stability, security, and performance.

Still snapping back after an update and a reopen? Resetting Firefox settings is the broader fix, and it is a blunt one: defaults come back, and this override goes with everything else you customized.

RELATED: Reset Mozilla Firefox Browser Settings on the Computer