How do I fix a slow browser?

Why browsers slow down and consume memory, and the checks that fix it — usually extensions and tabs rather than the browser itself.

Difficulty: beginner
Time: 30 min
Read: 2 min

Short answer

Close unused tabs, review and remove extensions you do not recognise, clear the cache, and make sure the browser is updated. Extensions are the most common cause — each one runs on every page, and a browser with twenty extensions is running twenty programs continuously.

A browser is effectively an operating system now, and it slows down for the same reasons one does: too much running at once, and things installed that you have forgotten about. Extensions in particular do far more work than most people realise.

What you'll need

Password manager to preserve logins (optional)

Step by step

Check how many tabs are open.Each tab holds a live page in memory. Fifty tabs can use more memory than everything else on the machine combined.
Review the extension list and remove anything you do not actively use.Each extension runs on every page load. This is the most common cause of a slow browser, and of the browser using large amounts of memory.
Remove anything you do not recognise entirely.Unrecognised extensions are the most common form of real browser malware and may be injecting adverts or tracking.
Clear the cache and cookies.It logs you out of sites, so make sure you can get back in. A password manager makes this painless.
Update the browser.Performance improvements are constant, and an out-of-date browser is also a security problem.
Check for a built-in performance or memory saver setting.Most browsers now offer to suspend inactive tabs, which substantially reduces memory use.
Try a guest or private window as a diagnostic.If it is fast there, the problem is extensions or profile data rather than the browser.
As a last resort, reset the browser or create a fresh profile.It clears accumulated state without reinstalling. Sync your bookmarks first.

Tips

Use a tab manager or bookmark folders instead of keeping dozens of tabs open. It is faster and easier to find things.
Ad blockers usually make browsing faster rather than slower, because they prevent a lot of scripts and trackers loading.
If only one site is slow, the problem is that site rather than the browser.

Common mistakes

Installing more extensions to fix performance — Extensions are usually the cause. Adding a performance extension adds another program running on every page.
Keeping dozens of tabs open permanently — Each one holds a live page in memory. It is the single largest memory consumer for many people.
Ignoring unrecognised extensions — They are the most common form of browser malware and can inject adverts or capture data.

Questions people ask

Why does my browser use so much memory?

Open tabs and extensions. Each tab holds a live page and each extension runs on every page load. Suspending inactive tabs and removing unused extensions addresses most of it.

Does clearing the cache help?

Sometimes, particularly if pages are rendering oddly. It logs you out of sites, so it is worth doing after checking extensions and tabs, which are more common causes.