For many people, the web browser is where almost all the work happens, and it is often the app using the most memory and processor time. A few changes can make a big difference to the whole Mac.
Close the tabs you are not using
Every open tab keeps a web page in memory, and many keep running scripts in the background, even when you are not looking at them. Dozens of tabs can use several gigabytes of memory.
- Close tabs you have finished with.
- Save pages for later with bookmarks, Safari's Reading List (Bookmarks > Add to Reading List), or Tab Groups.
- Quit and reopen the browser occasionally to clear out pages that have grown large over time.
Find the tab slowing everything down
Safari: open Activity Monitor, click CPU, and look for processes named after websites. Sort by % CPU or Memory to find the worst offender.
Chrome: choose Window > Task Manager (or press Shift-Esc on some versions). It lists each tab and extension with its memory and CPU use. Select one and click End process.
Pages with video, live dashboards, ads and web apps such as chat and email clients are common culprits.
Remove extensions you do not use
Extensions run on every page you visit, and some use a surprising amount of memory.
- Safari: choose Safari > Settings > Extensions. Untick extensions to turn them off, or select one and click Uninstall.
- Chrome: go to
chrome://extensions. Turn off or remove extensions you do not need.
If the browser speeds up with extensions off, turn them back on one at a time to find the slow one.
Chrome: Memory Saver and Energy Saver
In Chrome, open Settings > Performance:
- Memory Saver frees memory from tabs you have not used for a while. They reload when you click them.
- Energy Saver limits background activity on battery power.
Safari: keep it updated
Safari updates come with macOS updates. Install updates from System Settings > General > Software Update to get the latest performance improvements and fixes.
Clear cached data if pages misbehave
If a specific site loads slowly or looks broken, clearing its data often helps:
- Safari: choose Safari > Settings > Privacy > Manage Website Data, search for the site, and click Remove. Or choose Safari > Clear History to remove history and website data for a time range.
- Chrome: open Settings > Privacy and security > Delete browsing data, select Cached images and files, and delete.
Clearing cookies signs you out of websites, so choose only cached files if you want to stay signed in.
Try a fresh profile
If Chrome is still slow, create a new profile from the profile icon in the toolbar and try it for a day. If it is fast, something in your old profile, such as an extension or corrupted data, is the problem. In Safari, testing in a Private Window with extensions off gives a similar comparison.
Frequently asked questions
Why is Chrome using so much memory on my Mac?
Chrome runs each tab and extension in its own process. Many tabs, heavy websites and extensions add up. Close tabs, remove extensions and turn on Memory Saver.
Is Safari faster than Chrome on a Mac?
Safari is built by Apple for macOS and is generally efficient with memory and battery. Either can be fast if you keep tabs and extensions under control.
Will clearing my browser cache make it faster?
Usually not in general use, but it can fix specific sites that load slowly or behave strangely. Pages may load slightly slower straight afterwards while the cache rebuilds.
Want this done for you?
spacerecover scans your Mac for caches, old installers, app leftovers, large files and developer build-up, explains each one in plain words, and clears what you approve in one step. Items go to the Trash first, so you can undo.