Although it is colorful enough, we all despise that macOS spinning beach ball – especially when it regularly appears while browsing the web with Firefox.
Imagine that awkward moment when you have people watching your screen during a presentation and Firefox suddenly hangs and stops responding to your clicks.
The usual workaround is to force quit Firefox and likely launch the same webpage again using another browser like Safari or Google Chrome. Sound familiar?
The cause of Firefox running slow depends on the version of macOS that your Mac is running, the version of Firefox you are using and your typical browsing habits.
Some of the most common causes:
- Your browser is outdated.
- Firefox is using too many hardware resources, which causes your Mac to heat up.
- Firefox has created a lot of cache files and has a large browsing history, etc.
- Too many add-ons are being used.
- Other, resource-hogging applications are running, leaving Firefox with only a little memory space to process your requests.
- There are too many tabs open.
- Your Mac is slow in general, but you think Firefox is to blame.
How to Make Your Mac Faster Again
If the spinning wheel runs for too long and Firefox becomes unresponsive, the first step is to force quit the application. It is then recommended to restart your Mac so the operating system can perform its ’self-healing’ actions, such as emptying the cache and clearing any temporary files. If your Mac becomes unresponsive, hard reset the machine by pressing and holding the power button for a few seconds and then pressing again to restart the computer.
After the restart, it's good to first start by checking the version of Firefox you are using. Achieve this with these following steps:
- In the menu bar, click on “Firefox”.
- Select “About Firefox”.
- A pop-up window will inform you whether the browser it up to date or not. If the software is out-of-date, hit the update button.
Mac Getting Hot
While macOS does a good job of optimally using the computer's hardware resources, it is recommended that you use a monitoring tool such as Activity Monitor. It's extremely useful if you are encountering app performance issues, such as Firefox running slow or even if your Mac is becoming hot while running.
If you notice some slowdown in Firefox’s performance followed by a crash, that’s likely because Firefox is using more memory than it should. The best way to start the fix is by analyzing the extensions, themes and plugins, and activating the Firefox hardware acceleration feature.
Firefox Extensions and Themes
Extensions and themes can consume memory, and you can determine if these are causing the issue by starting Firefox in Safe Mode:
- Click on the menu button.
- Select “Help” and then “Restart with Add-ons Disabled”.
- Firefox will launch with the Firefox Safe Mode dialog box.
If the problem doesn't occur in Safe Mode, it is likely caused by an extension or one of your themes so you will want to disable or uninstall extensions.
If the problem persists in Safe Mode, start by clearing cookies and the cache, and restart in Safe Mode again. If this still doesn’t fix the problem, try reinstalling Firefox or inspecting your plugins.
Some web pages contain content that uses system memory to properly display, although you don't really need them. There are extensions and plugins that allow you to block such content: Flashblock, for example, selectively enables and disables Flash content on websites; additionally, No-Script Suite achieves the same but for scripts.
If you don't update those plugins regularly, you'll end up with a slow web browser since they can consume large amounts of memory. To check whether they are up to date, visit Firefox's dedicated Plugin Check page.
Of course, you can always spot whether a faulty plugin is causing the performance slowdown by selectively disabling some of them. You can do so in the Add-ons Manager tab.
- Click the menu button.
- Choose “Add-ons”.
- In the Add-ons Manager tab simply select the Plugins panel.
Hardware acceleration – although helpful – can sometimes cause issues, due to the wide range of possible driver, video card and operating system combinations. So if you are hoping for improved Firefox (and Mac) performance you might want to turn off hardware acceleration. You can do that by:
- Pressing the Cmd +, keys to open the Preferences window.
- Selecting the Advanced panel.
- Selecting the General tab.
- Unchecking the “Use hardware acceleration when available” option.
You may want to “improve” your web browsing habits as well. For instance, only opening one window and closing any tabs you don't need will reduce the memory used by Firefox. Having tons of tabs open will slow down your Mac since it forces the operating system to allocate more resources (such as CPU or RAM) to the browser.
If Firefox is still causing issues, try switching to a different browser such as Safari or Google Chrome. Sometimes Firefox doesn't work well under certain versions of macOS. You can always report problems to Firefox by sending crash reports and hope that the developers of the non-profit organization will react rapidly and push out an update to patch the issue.