Firefox Is Slow? 10 Fixes That Actually Work

Firefox was fast when you first installed it, and now every click feels like it’s wading through syrup. That gap between “new browser” and “current browser” almost always comes down to a handful of causes: extensions piling up, hardware acceleration fighting your graphics driver, a profile carrying years of history and cache, or simply too many tabs sitting open at once. The good news is Mozilla has an official order for working through these, and none of it requires reinstalling anything. This guide walks through that order, plus what each fix actually costs you (an extension, a setting, sometimes your open tabs) and how to protect your tabs before you touch anything.

Why Is Firefox Slow?

Firefox slows down for a small set of repeat-offender reasons: extensions and themes, hardware acceleration issues, a bloated or corrupted profile, and simply having too many tabs open. Mozilla’s own troubleshooting guidance for Firefox “closing or quitting unexpectedly” lists updating Firefox, Troubleshoot Mode, disabling extensions and hardware acceleration, refreshing Firefox, a new profile, a malware check, and updated graphics drivers, in that order.

The table below maps common symptoms to the fastest fix, so you can jump straight to the section that matches what you’re seeing instead of reading the whole guide top to bottom.

This is a Firefox-wide guide, not a crash guide. If Firefox is closing or quitting on you, not just running slowly, the fixes overlap but the order matters more. Our Firefox keeps crashing guide covers that scenario step by step.

How Do I Speed Up Firefox Right Now?

Start with the fixes that cost you nothing and take under a minute, before you touch extensions or profiles. These won’t fix a deeper problem, but they clear out the easy causes first and often solve it outright.

None of this is exotic, and that’s the point. A lot of “Firefox is slow” complaints get solved by step 2 alone, especially for anyone who treats tabs like a to-do list and never closes them. If you’re one of those people, our guide on dealing with too many tabs goes deeper into keeping that under control without losing anything.

Is Firefox Slow Because of Too Many Extensions?

It might be, and Troubleshoot Mode is how you find out. Restart Firefox in Troubleshoot Mode by opening the menu button, going to Help, and choosing Troubleshoot Mode, or by holding Shift while Firefox launches. This disables every extension and theme and turns off hardware acceleration in one step, which isolates whether any of those three are the cause.

If Firefox runs normally in Troubleshoot Mode, one of those is responsible. If the problem persists there too, it isn’t an extension, theme, or hardware acceleration issue, and you can skip straight to the profile and refresh sections below without wasting time disabling extensions one by one.

Narrow it down once you know it’s an extension. Re-enable your extensions a few at a time from the Add-ons manager instead of all at once, and restart normally between batches. It takes longer, but you’ll know exactly which extension to remove instead of guessing. Our Firefox extensions guide is a reasonable place to start if you end up needing replacements.

Extensions that inject themselves into every page you visit, run background scripts constantly, or haven’t been updated in a long time are the usual suspects. It’s worth periodically auditing what’s installed even when things feel fine, since an extension that was fine last year can start misbehaving after a Firefox update changes how it’s allowed to run.

Does Firefox Use Too Much Memory?

Often, yes, especially with a lot of tabs open, but Firefox has a built-in feature to manage this without closing anything for you. Firefox can unload tabs you aren’t actively using, which frees memory and CPU while keeping the tab available to revisit later. This was added in Firefox 140, and Firefox also triggers it automatically when your system is low on memory, while avoiding tabs that are playing media, using Picture-in-Picture, or on a call through WebRTC.

You can see and control this yourself by typing about:unloads into the address bar. It lists your open tabs in unload priority order along with last access time and memory use, with an Unload button next to each one.

This is genuinely useful, but it’s a memory management tool, not a tab-saving tool. An unloaded tab still counts against your open-tab total, still needs Firefox running to exist, and still disappears if the window closes or Firefox crashes before it’s unloaded. If your real problem is “I have 80 tabs open because I’m scared to close them,” unloading doesn’t solve that; saving them somewhere durable does.

How Do I Refresh Firefox Without Losing My Tabs?

Refresh Firefox from about:support, and it will not touch your open tabs, bookmarks, passwords, or history. What it removes is your extensions and their data, themes, custom preference changes, and any custom userChrome or userContent CSS you’ve added. Here’s exactly what happens to each side.

Refresh is a genuinely good option when Troubleshoot Mode confirmed an extension or setting is the problem but you don’t want to hunt for which one. It’s a broader reset than disabling one extension, and Mozilla’s guidance treats it as the standard next step after Troubleshoot Mode when the issue doesn’t clear up on its own.

Should I Disable Hardware Acceleration in Firefox?

Try it if Refresh and Troubleshoot Mode haven’t fully solved things, particularly if you’re also seeing glitchy video or choppy scrolling. Hardware acceleration uses your graphics card to speed up rendering, but certain graphics drivers or processors cause crashes or rendering glitches when it’s on, which is why Mozilla lists disabling it as a specific troubleshooting step separate from Troubleshoot Mode.

You already tested this indirectly: Troubleshoot Mode turns off hardware acceleration along with extensions and themes, so if that mode fixed things, hardware acceleration could be part of why. To isolate it on its own, keep extensions enabled but turn off hardware acceleration in Firefox’s settings and see if the problem clears up.

Update your graphics drivers before you give up on hardware acceleration. Outdated graphics drivers are a common cause of the exact glitches hardware acceleration is supposed to prevent. Mozilla lists updating to the latest drivers from your graphics card manufacturer as its own troubleshooting step, and it’s worth doing before you permanently turn the feature off.

Hardware acceleration genuinely does help performance when your drivers are current and compatible, so don’t treat “turn it off” as a free lunch. It’s a trade: you get more stable rendering at the cost of some GPU offloading. On older or budget hardware, especially, this trade-off can favor leaving it off permanently.

What If Firefox Is Slow to Start Up?

Slow startup usually traces back to extensions loading at launch, a large profile, or Firefox reopening a heavy session from last time. If “Open previous windows and tabs” is turned on under Settings > General > Startup, Firefox reloads every tab and window you had open the moment it launches, and a session with dozens of tabs takes real time and memory to rebuild.

Mozilla has a dedicated article specifically for Firefox crashing or struggling at startup, separate from its general crash guidance, because startup problems sometimes need different fixes than problems that happen mid-session. If Firefox is unstable enough that troubleshooting inside it is hard, the Troubleshooting Information page (about:support) can still gather diagnostics even in that state.

If you’d rather not have Firefox reopen your last session automatically at all, our guide to Firefox’s restore-last-session behavior covers how that setting works and how to control it.

How Do I Fix Firefox If It’s Slow After a Crash?

Check about:crashes first to see whether Firefox crashed or just felt slow, since the fix differs. Typing about:crashes in the address bar shows submitted and unsubmitted crash reports, each with a Report ID starting with “bp-” that’s useful if you ask for help in Mozilla’s support forum.

If Firefox did crash, Mozilla’s official order applies: update Firefox, try Troubleshoot Mode, disable extensions and hardware acceleration, refresh, create a new profile, check for malware, and update graphics drivers. After a crash where the automatic restore fails, Firefox shows a Session Restore page letting you pick which tabs to bring back; this should only appear after a failed auto-recovery, not on a routine restart.

If crashing rather than slowness is your main issue, our full Firefox keeps crashing guide walks through this scenario in more depth, including how to locate and recover those session backup files manually.

How Do I Create a New Firefox Profile to Fix Slowness?

Create a new profile through about:profiles if Refresh Firefox didn’t solve ongoing slowness or crashing, since Mozilla recommends this specifically to rule out a corrupted profile. A profile holds everything Firefox knows about your setup: bookmarks, history, passwords, extensions, and cache, all in one folder. Over years of use, that folder can accumulate corruption that a simple refresh doesn’t fully clear.

Find your current profile folder through about:support or about:profiles, which also lets you create a fresh one and set it as default. This is a bigger step than refreshing, since a genuinely new profile starts with none of your saved logins, bookmarks, or history unless you migrate them over manually.

Back up before you go this far. A new profile is the closest thing to a factory reset that Firefox offers. Export your bookmarks, and export or save your open tabs as a session, before you switch profiles, so you’re migrating deliberately instead of starting from zero.

This is also where Firefox’s own troubleshooting steps run out for tabs specifically. Mozilla’s process is built around fixing the browser, not around guaranteeing your open tabs survive every step of that process intact. That gap is worth covering directly, since it’s the part most people get burned by.

How Do I Keep My Tabs Safe While Troubleshooting Firefox?

Save your tabs as a named session before you start any of the fixes above, since a new profile, a corrupted sessionstore file, or an accidentally closed Private Browsing window can each cost you tabs Firefox itself can’t get back. Firefox’s own session recovery is solid for routine restarts and even most crashes, but it has real limits: Private Browsing windows are never restored, deliberately, and the crash-recovery page only appears when automatic restore fails.

This is exactly the gap BelayTab fills. It’s a free extension, with no account required, that saves your open tabs as a named session with one click or with Ctrl+Shift+S (Cmd+Shift+S on Mac). It also snapshots every open window automatically, on a five-minute timer and again when a window closes, so you’re covered even if you forget to save manually before you start troubleshooting. Tab groups, pinned tabs, and tab order are preserved, and the free plan keeps unlimited sessions plus the last 20 versions of each one, so restoring never overwrites your history, it just adds to it.

If you’re already using another way to keep tabs, BelayTab imports sessions from OneTab, Session Buddy, Tab Session Manager, and Tablerone, and it exports to JSON, CSV, a plain URL list, or HTML bookmarks, so switching doesn’t mean starting over. It runs on Chrome, Edge, Brave, Opera, Vivaldi, Arc, Firefox, and Safari on Mac, and it doesn’t need permission to read anything on the pages you visit.

Restore before you troubleshoot, not after. Every Recovery screen in BelayTab pulls together automatic snapshots, deleted sessions in a 30-day trash, and your browser’s recently closed windows, in one place. If a profile switch or a refresh goes sideways, that’s where your tabs are waiting.

For anyone comparing tab-saving tools rather than starting from scratch, our session manager comparison and our tab manager guide both cover how the free options differ in practice.

What Else Can I Try If Firefox Is Still Slow?

Work through malware scanning and graphics driver updates next, since Mozilla lists both as part of its official crash and slowdown troubleshooting, even though they get less attention than extensions or profiles. A malware or adware scan rules out something running outside Firefox that’s dragging it down, and it’s a reasonable step even if you’re confident about what’s installed, since some adware specifically targets browsers.

Graphics driver updates matter more than most people expect, particularly if you’ve already ruled out extensions through Troubleshoot Mode and Firefox is still stuttering on anything visual. Get the latest driver directly from your graphics card manufacturer’s site rather than relying on whatever your operating system installed automatically, since manufacturer drivers are usually newer.

When none of this is enough. If you’ve gone through updating, Troubleshoot Mode, unloading tabs, refreshing, a new profile, a malware check, and driver updates, and Firefox is still consistently slow, that points toward a hardware limitation rather than a software fix. At that point, reducing how many tabs and windows you keep open at once, and saving the rest as sessions you reopen only when needed, does more than any setting change.

Working through a list this long can feel discouraging, but you rarely need all of it. Most people find their answer in Troubleshoot Mode or a Refresh, and the remaining steps exist for the smaller number of cases those two don’t fix. Go in order, test after each step, and don’t skip straight to a new profile just because it sounds thorough; it’s the most disruptive fix on this list, not the most likely one to be necessary.

Whatever you end up trying, treat your open tabs as something worth protecting on purpose rather than something that happens to survive. Firefox’s built-in tools handle a lot of that already, but they weren’t designed to guarantee every tab through every kind of troubleshooting. A saved session takes a few seconds and removes that risk from the rest of this list entirely.