Q: Safari crashing each time I open it.

If Safari is slow, stops responding, quits unexpectedly, or has other issues

Unsupported third-party add-ons may cause Safari to unexpectedly quit or have performance issues

Safari/Preferences/Advanced - enable the Develop menu, then go there and Empty Caches. Quit/reopen Safari and test. Then try Safari/History/Show History and delete all history items.  Quit/reopen Safari and test. You can also try try Safari/Clear History and Web Site Data. The down side is it clears all cookies.Doing this may cause some sites to no longer recognize your computer as one that has visited the web site. Go to Finder and select your user/home folder. With that Finder window as the front window, either select Finder/View/Show View options or go command - J.  When the View options opens, check ’Show Library Folder’. That should make your user library folder visible in your user/home folder.  Select Library./Caches/com.apple.Safari/Caches.db and move it to the trash.

Go to Safari Preferences/Extensions and turn all extensions off. Test. If okay, turn the extensions on one by one until you figure out what extension is causing the problem.

Safari Corruption       See post by Linc Davis

Launch the Console application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

Step 1

For this step, the title of the Console window should be All Messages. If it isn't, select

          SYSTEM LOG QUERIES ▹ All Messages

from the log list on the left. If you don't see that list, select

          View ▹ Show Log List

from the menu bar at the top of the screen.

In the top right corner of the Console window, there's a search box labeled Filter. Enter the name of the crashed application or process. For example, if Safari crashed, you would enter "Safari" (without the quotes.)

Each message in the log begins with the date and time when it was entered. Select the messages from the time of the last crash, if any. Copy them to the Clipboard by pressing the key combination command-C. Paste into a reply to this message by pressing command-V.

The log contains a vast amount of information, almost all of which is irrelevant to solving any particular problem. When posting a log extract, be selective. A few dozen lines are almost always more than enough.

Please don't indiscriminately dump thousands of lines from the log into this discussion.

Please don't post screenshots of log messages—post the text.

Some private information, such as your name, may appear in the log. Anonymize before posting.

Step 2

In the Console window, select

          DIAGNOSTIC AND USAGE INFORMATION ▹ User Diagnostic Reports

(not Diagnostic and Usage Messages) from the log list on the left. There is a disclosure triangle to the left of the list item. If the triangle is pointing to the right, click it so that it points down. You'll see a list of crash reports. The name of each report starts with the name of the process, and ends with ".crash". Select the most recent report related to the process in question. The contents of the report will appear on the right. Use copy and paste to post the entire contents—the text, not a screenshot.

I know the report is long, maybe several hundred lines. Please post all of it anyway.

If you don't see any reports listed, but you know there was a crash, you may have chosen Diagnostic and Usage Messages from the log list. Choose DIAGNOSTIC AND USAGE INFORMATION instead.

In the interest of privacy, I suggest that, before posting, you edit out the “Anonymous UUID,” a long string of letters, numbers, and dashes in the header of the report, if it’s present (it may not be.)

Please don’t post other kinds of diagnostic report—they're very long and rarely helpful.

When you post the log extract or the crash report, you might see an error message on the web page: "You have included content in your post that is not permitted," or "The message contains invalid characters." That's a bug in the forum software. Please post the text on Pastebin, then post a link here to the page you created.

That's not a complete crash report. There should be at least one that's much longer, several hundred lines.

If Safari crashes on launch and you don't have another web browser, you should be able to launch Safari by starting up in safe mode.

You may have installed the "Genieo" or "InstallMac" ad-injection malware. Follow the instructions on this Apple Support page to remove it.

Back up all data before proceeding.

Malware is always changing to get around the defenses against it. In addition to the files listed in the support article, you may also have some of the following:

~/Library/LaunchAgents/com.Installer.completer.download.plist

~/Library/LaunchAgents/com.Installer.completer.ltvbit.plist

~/Library/LaunchAgents/com.Installer.completer.update.plist

~/Library/LaunchAgents/com.spigot.SearchProtection.plist

~/Library/Application Support/IM.Installer

Removing these files, if they exist, is optional if you've already followed Apple's instructions.

One of the steps in the article is to remove malicious Safari extensions. Do the equivalent in the Chrome and Firefox browsers, if you use either of those.

After removing the malware, remember to reset your home page in all the web browsers affected, if it was changed.

If you don't find any of the files or extensions listed, or if removing them doesn't stop the ad injection, then you may have one of the other kinds of adware covered by the support article. Follow the rest of the instructions in the article.

If you find Apple's instructions too hard to follow, ask for an alternative that doesn't require you to trust a black-box application without knowing what it does.

Make sure you don't repeat the mistake that led you to install the malware. Chances are you got it from an Internet cesspit such as "Softonic," "CNET Download," or "SourceForge." Never visit any of those sites again. You might also have downloaded it from an ad in a page on some other site. The ad would probably have included a large green button labeled "Download" or "Download Now" in white letters. The button is designed to confuse people who intend to download something else on the same page. If you ever download a file that isn't obviously what you expected, delete it immediately.

In the Security & Privacy pane of System Preferences, select the General tab. The radio button marked Anywhere  should not be selected. If it is, click the lock icon to unlock the settings, then select one of the other buttons. After that, don't ignore a warning that you are about to run or install an application from an unknown developer.

Still in System Preferences, open the App Store or Software Update pane and check the box marked

          Install system data files and security updates (OS X 10.10 or later)

or

          Download updates automatically (OS X 10.9 or earlier)

if it's not already checked.