Most of the time Apple’s Safari browser is a reliable, versatile and speedy portal to the web. Just occasionally, however, the entire application can be brought to a standstill seemingly by nothing. If this becomes a regular problem, the list below should help you find a cause. These aren’t just limited to Safari either; many of them can affect other browsers as well.
Too many windows
Each Safari window open on your Mac will takes up space in memory. Each window may also be fighting for your computer’s other resources, as webpages often require heavy use of your network, processor and graphics card as well. When any of these is too busy, Safari will appear to grind to a halt.
Too many tabs
Although it may appear that tabs aren’t really open, each one still has full access to your resources. Try playing music in a tab and notice that it continues to play when you switch to another. Webpages open in tabs still take up nearly as much memory as a full window, so try to clean up unnecessary tabs once in a while.
Do you know how often Safari is updated? Every night a new version of WebKit, the rendering engine behind Safari, can be downloaded from nightly.webkit.org. While updating nightly will do little to stop Safari from crashing (and the nightly builds are actually more likely to be buggy), it is always worth making sure that you are running the latest version, by running Software Update from the Apple menu.
If you’re still running Leopard or earlier, you may also want to consider upgrading your OS. Under Snow Leopard, Safari can usually let a plugin or tab crash without bringing down the whole browser.
So that Safari doesn’t have to download the same stuff over and over again, it stores some web page content on your hard drive in a cache. This way Safari doesn’t have to download the same Google logo every time you want to do a web search, for example.
Sometimes, however, web pages change. If safari tries to mix cached content and new web content, sometimes these aspects aren’t compatible with each other. Often this can result in a page not loading correctly, but occasionally it can confuse Safari enough to cause a crash. Thankfully, the cache can be manually emptied by selecting Empty Cache from the Safari menu.
Culinary jokes aside, bad cookies have an unfairly bad reputation. In reality most cookies are nothing to fear, they cannot directly spy on you or delete your hard drive, cookies are simply pieces of data websites store on your computer for your convenience.
If a poorly designed, out-dated or corrupted cookie is stored on your system, and a website doesn’t handle it correctly, this may result in a crash, although it is more likely the website will simply not function correctly. If this continues, cookies can be deleted either individually or on mass from the Security tab of Safari’s preferences.
As well as cookies, Safari also stores information for some HTML5 websites in database storage. If HTML5 websites are causing issues these may have become corrupted. They can be deleted in that same way as cookies.
Apple’s comments on Flash’s unreliability aren’t without merit. Flash may be a common and powerful platform, but because Flash software tends to be heavy on resources and runs on several platforms, it can be unreliable. Occasionally this results in Safari crashing outright, but more often than not Flash is just a cause of serious slowdown.
If you find Flash content is continually chugging on your Mac, try right clicking on some Flash content, clicking “Settings” and toggling hardware acceleration. On some machines this may make all the difference.
Flash isn’t the only type of software run by your browser. Other plugins, such as Java, Silverlight and various media players constantly run their own web content. If you notice a plugin is causing Safari to crash often, make sure you have the latest version. Some plugins update automatically, but others use preference panes, or require you to manually download and install the new version. If the latest version is still unstable, there may be an alternative plugin for the same content, especially for videos and audio.
If you use a lot of RSS or other news feeds and have them set to automatically update, these may be causing Safari to slow to a crawl and crash. You can set which RSS feeds are updated and how often in the RSS tab in Safari’s preferences.
Internet Explorer on Windows still holds the greatest browser market share by a good margin. This means many websites aren’t designed using full web standards and aren’t fully tested on Safari. Usually these websites won’t cause a full crash, but you may need to use a different browser, such as Firefox, for them to display properly.
Extensions are usually very small, simple programs that improve your web experience. Often, however, extensions will run code every time that you load a new page. This quickly adds up so consider uninstalling, or disabling extensions that you don’t really need. If an extension is a particular resource hog, or often crashes, see if an update or similar alternative is available.
Sometimes Safari will crash through no fault of its own. Occasionally, other applications may clash with Safari, trying to access resources at the same time. This is especially true of applications relating to preference management, networking or security. For example, some banks encourage their customers to install security software called Rapport. Some older versions of Rapport have been known to cause issues with some versions of Safari.
Most virus scanners will let Safari get on with it’s work unhindered, if your workplace insists on particularly high security, however, and you have any unusual extensions or scripts installed, you may find them blocked. If any of the blocked files are key to software, it may bring Safari down with it.
If you use a third-party firewall or unusual network arrangement you may find some functionality of Safari being blocked. Usually the firewall will tell you this has happened, but if you miss the notification, or have them disabled, it may appear the Safari has simply locked up.
If you sometimes use a proxy server and have ever fiddled with your network settings, sometimes when you switch to another network these settings can confuse Safari to the point of crashing. To avoid this set up a new location in network preferences using different settings.
Pop-ups / ads
When Safari seems to be grinding to a halt and you’ve only got a text article open, run expose to check for pop-under ads. The default popup blocker can be activated from the Safari menu. Even with Safari’s pop-up blocker activated, sometimes the odd window will sneak through, and even some embedded ads can be fairly resource intensive.
Not Enough Ram
If you find that your Mac is constant struggling with displaying multiple tabs or windows it may be time to invest in an upgrade. Buying more RAM is the least expensive way to upgrade most Macs.
Bad scripts and practical jokers
Unlike apps, anyone can make and publish a web script. This means many scripts are poorly written and some, such as those found on crashmybrowser.com, are deliberately designed to crash your web browser. Sometimes these are designed to bring down your browser’s defences, but most of them are designed for testing or pranking colleagues.
If Safari is really playing up, and crashes whenever you start it up, or whenever you use a common feature, such as bookmarks, your preferences may have become corrupt. In this scenario, navigate to Safari’s preference folder (~/Library/Safari/) in Finder and delete the relevant files. Deleting Bookmarks.plist, for example, will reset your bookmarks. Remember that doing this will delete all your data, so you may want to make a backup of these files first.
If you delete everything in this folder, Safari will be fully reset to its factory default settings, and all your data will be lost.
Probably the most common cause of crashes is impatience. Safari can survive nearly all crashes without closing completely. In the minute it takes to recover, however, most users have already clicked Force Quit.