Safari slows my MacBook Pro

Back up all data before proceeding.

Quit Safari if it’s running. Then select

 ▹ Force Quit…

from the menu bar. A small window will open with a list of running applications. Safari may appear in that list, even though you quit it. If so, select it and press return. Close the window.

Step 1

Hold down the option key and select

Go ▹ Library

from the Finder menu bar. Delete the following items from the Library folder (some may not exist):

Caches/com.apple.Safari

Caches/com.apple.Safari.SearchHelper

Caches/com.apple.SafariServices

Caches/com.apple.WebKit.PluginProcess

Caches/com.apple.WebProcess

Caches/Metadata/Safari

Preferences/com.apple.WebKit.PluginHost.plist

Preferences/com.apple.WebKit.PluginProcess.plist

Saved Application State/com.apple.Safari.savedState

Leave the Library folder open. Try Safari again. If the problem is solved, stop here. Close the Library folder. If you still have a problem, continue.

Step 2

Move the following items from the open Library folder to the Desktop (again, some may not exist):

Cookies/Cookies.binarycookies

Internet Plug-Ins

Preferences/ByHost/com.apple.Safari.*.plist

Preferences/com.apple.Safari.Extensions.plist

Preferences/com.apple.Safari.LSSharedFileList.plist

Preferences/com.apple.Safari.plist

Preferences/com.apple.WebFoundation.plist

PubSub/Database

Safari

SyncedPreferences/com.apple.Safari.plist

Here, "*" stands for a long string of letters, numbers, and dashes.

Note 1: You are not moving the Safari application. You’re moving a folder named “Safari.”

Note 2: This step will remove your Safari extensions, if any, and their settings. If you choose to reinstall them, do so one at a time, testing each time to make sure you haven’t restored the problem.

Try again. Your settings and bookmarks will be lost. The default set of bookmarks will be restored. Delete them all.

If Safari is now working normally (apart from the lost settings), look inside the “Safari” folder on the Desktop for a file named “Bookmarks.plist”. Select

File ▹ Import Bookmarks...

from the Safari menu bar. Import from that file. Recreate the rest of your Safari settings. You can then delete the items you moved to the Desktop.

If the issue is still not resolved, quit Safari again and put all the items you moved to the Desktop back where they were, overwriting the newer ones that may have been created in their place. You don’t need to replace the files you deleted in Step 1. Stop here and post again.

If you don’t like the results of the last step, you can undo it completely by quitting Safari and restoring the items you moved or deleted in that step from your backup, overwriting any that were created in their place.

If you no longer have the problem, there's no need to do anything else. I don't know what caused it.

Please read this whole message before doing anything.

This procedure is a test, not a solution. Don’t be disappointed when you find that nothing has changed after you complete it.

Step 1

The purpose of this step is to determine whether the problem is localized to your user account.

Enable guest logins* and log in as Guest. Don't use the Safari-only “Guest User” login created by “Find My Mac.”

While logged in as Guest, you won’t have access to any of your documents or settings. Applications will behave as if you were running them for the first time. Don’t be alarmed by this behavior; it’s normal. If you need any passwords or other personal data in order to complete the test, memorize, print, or write them down before you begin.

Test while logged in as Guest. Same problem?

After testing, log out of the guest account and, in your own account, disable it if you wish. Any files you created in the guest account will be deleted automatically when you log out of it.

*Note: If you’ve activated “Find My Mac” or FileVault, then you can’t enable the Guest account. The “Guest User” login created by “Find My Mac” is not the same. Create a new account in which to test, and delete it, including its home folder, after testing.

Step 2

The purpose of this step is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login, by a peripheral device, by a font conflict, or by corruption of the file system or of certain system caches.

Please take this step regardless of the results of Step 1.

Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards, if applicable. Start up in safe mode and log in to the account with the problem.

Note: If FileVault is enabled in OS X 10.9 or earlier, or if a firmware password is set, or if the startup volume is a software RAID, you can’t do this. Ask for further instructions.

Safe mode is much slower to start up and run than normal, with limited graphics performance, and some things won’t work at all, including sound output and Wi-Fi on certain models. The next normal startup may also be somewhat slow.

The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.

Test while in safe mode. Same problem?

After testing, restart as usual (not in safe mode) and verify that you still have the problem. Post the results of Steps 1 and 2.