Symptoms
- Pages take a long time to load
- Scrolling or typing feels laggy
- Browser freezes briefly then recovers
- Fan spins up when browser is open
Likely causes
- CommonToo many open tabsEach tab uses memory and CPU even in the background.
- CommonBloated cache or historyYears of cached data can slow lookups and disk access.
- CommonA misbehaving extensionExtensions run on every page and a bad one can consume CPU constantly.
- PossibleOutdated browser versionOld versions miss performance fixes and security patches.
- PossibleToo many background browser processesSome sites and extensions spawn hidden processes that add up.
What to do
- Close tabs you are not actively using; bookmark anything you want to keep for later.
- Restart the browser completely to clear temporary memory buildup.
- Open the browser's task manager (Shift+Esc in Chrome, about:processes in Firefox) to see which tab or extension is using the most CPU or memory.
- Disable extensions one at a time, restarting the browser after each, to find the culprit.
- Clear cached images and files from browser settings; this will not delete saved passwords or bookmarks.
- Check for and install any pending browser updates.
- If the problem persists, create a new browser profile and see if it is faster.
When to call a pro
If the whole computer is slow, not just the browser, get it checked for malware or hardware issues.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.