As its rivals roll over their version numbers with each minor change, Safari 5.1, plays it cool. That humble decimal upgrade, from 5.0 to 5.1, encompasses significant changes to Apple’s browser that help it compete far more respectably than its predecessor. The latest version also packs a few new surprises. Safari ships with Lion, but it's also available as an upgrade for Snow Leopard.

Safari 5.1 owes its most visible changes to OS X Lion itself, which enables several features not available to Snow Leopard users. The new gesture-based controls Apple uses throughout the OS apply to Safari, too, including two-finger taps to zoom and swipes to navigate your browser history. Thanks to Lion’s new resume feature, Safari can remember its state when you quit and restore it when you reopen the browser.

In addition, Lion enables full-screen surfing, although this mode frustratingly hides the handy Bookmarks Bar. If you keep all your favourite links there, as I do, moving your cursor all the way to the top of the screen, then waiting a half-second or so for the menubar and Bookmarks Bar to appear, may get old fast. In its favour, the full-screen Safari window becomes its own workspace, so you can use Lion’s three-finger-swipe gesture to slide Safari off the side of the screen and work in other apps; swipe back to resume browsing. This is a great, easy way to conserve screen space when you have multiple programs open.

The new version introduces Reading List, a slick way to save the URLs of interesting pages for easy future reading. Sure, you could do the same thing with bookmarks, and plenty of third party addons and web services (such as Instapaper or Read It Later)  have long let you squirrel away lengthy online articles. But for anyone who simply wants to set aside the occasional intriguing piece for later, Reading List is easy to add to, use and manage.

The cure for “too long, didn’t read”: Reading List stashes lengthy articles for your future perusal.

Safari’s Reader feature, which displays articles in an easier-to-read format, sans ads and other clutter, has been significantly improved in Safari 5.1. Whereas Reader in Safari 5 often failed to correctly display articles, especially those spanning multiple pages, Safari 5.1’s Reader worked with every article I tested, even those that gave Safari 5’s version fits.

Reading List works with Reader mode, but only just. When you enter Reader mode while perusing a Reading List item, Safari is smart enough to stay in Reader when you switch to another Reading List item. But in all other cases, Safari displays saved items as ordinary web pages, regardless of how you were viewing each when you added it, and even if you were looking at it in Reader mode the last time you used Reading List.

Since I usually download only one or two files at any given time, I like Safari 5.1’s new Downloads display. Previous versions of Safari opened a separate window to track in-progress downloads, which either obscured your browsing or got lost in the background. Now, a small button with a miniature progress bar sits in the upper-right corner of Safari’s window, revealing a more traditional list of downloads, in an iOS-style popover, when clicked.

You can even drag completed downloads straight from this list to the desktop, a Finder window or another program. Those who frequently download multiple files simultaneously will probably miss the older approach. In Safari 5.1 you need to view that popover display to track the progress of each download, and doing anything else in Safari hides the list, but it seems to be an improvement on the whole.

In iOS, Apple seems to want to steer users away from web apps and into dedicated applications, often Apple’s own offerings. Safari 5.1 cleverly co-opts that strategy: When you first log in to a Gmail, AOL or Yahoo account, Safari offers to transfer your email, chat and calendar settings to Mail, iChat and iCalrespectively. I tested this feature with Yahoo Mail, and my Mail Inbox promptly displayed all the spam I’d happily ignored in webmail.

Behind the scenes, Safari 5.1 adds admirable privacy protections. Before autofilling information in web forms, the browser asks your permission and even lets you specify whether to pull info from Address Book or Outlook. A new Privacy pane in Safari’s Preferences also better illuminates the websites tracking you. Rather than displaying a tangle of filenames, Safari 5.1 lists domains and the types of files, cookies, caches, plugins and the like, each has stored on your Mac. You can delete these items by domain or all at once.

Cookie-to-English translation: Among other privacy improvements, Safari 5.1 makes it easier to see who’s tracking you, and how.

Under Lion, Safari joins Google’s Chrome browser in “sandboxing” its operations to further secure the browser. According to Apple, Safari walls off each individual online interaction it makes, preventing any site’s malicious code from exploiting any other site you’re browsing or from spreading to your Mac.

In both Lion and Snow Leopard, Safari 5.1 also separates what it’s doing online from the processes actually that run the browser. In theory, even if one or more sites load slowly, or include content that would in the past bring Safari to a crawl, Safari 5.1 will still open menus and new tabs responsively. In my testing, Safari 5.1 did slow down when digesting resource-heavy sites, but it never completely locked up.

Under the hood, Safari 5.1 for Lion adds hardware acceleration for HTML5 Canvas, which enables animations, games and other online apps. Though a few of the Canvas demos I tested wouldn’t work, most ran swiftly and smoothly. WebGL 3D demos and games also worked well. Inexplicably, this capability is turned off by default, with the setting buried in the hidden Develop menu. You can enable this menu on the Advanced screen of Safari’s preferences window.

My Safari tests found a few weird glitches. One particularly long article, viewed in Reader, initially choked Safari hard enough to crash the browser, although it worked fine on the second try. And Safari can mistake a two-finger horizontal swipe, meant to go forward or back in the current tab’s history, for an attempt to scroll horizontally. On sites with blank space on each size, this can leave pages hanging half-off the edge of the browser window. In general though, version 5.1 felt much faster and more capable than Safari 5.0, and at least on par with Firefox 5.

The XHTML results are in seconds, shorter times are better. The SunSpider JavaScript and CSS results are in milliseconds, shorter times are better. The Acid3 result is a score out of 100. The CSS3 Selectors result is a score out of 41. The HTML5 Compliance result is out of 321 with 13 bonus.

I performed my standard browser benchmarks on Safari 5.1 using a 2GHz aluminum-unibody MacBook with 2GB of memory. Based on these tests, version 5.1 maintains Safari’s traditional lead in rendering pages and improves notably in HTML5 support. However, it falls behind its rivals in JavaScript performance.

Safari 5.1 renders XHTML nearly 30 percent faster than Chrome 12, three times faster than Firefox 5 and four times faster than Opera 11.5. In CSS rendering, Safari 5.1 was a little slower than Safari 5.0.5 and just barely faster than Chrome, but it soundly clobbered Opera and Firefox.

Safari 5.1 ranked second in HTML5 compatibility, at 307 points (and 11 bonus points) out of 450. That’s 50 points better than Safari 5, but still 20 points behind Chrome. In the SunSpider JavaScript benchmark, Safari 5.1 finished last, 80 milliseconds slower than winner Firefox, although just 21 milliseconds slower than the nearest contender.

Note that this score may vary depending on your machine. In a separate test on a 2.66GHz MacBook Pro with a Core i7 processor, 4GB of memory and Snow Leopard installed, Safari 5.1’s SunSpider score (239.7 milliseconds) beat Chrome 12’s (401.6 milliseconds) by more than 40 percent.

In my testing under Snow Leopard, Safari 5.1 posted performance similar to what it registered on Lion.

XHTML rendering scores were nearly identical between Safari 5.0.5 and 5.1, CSS benchmarks ran slightly slower on the newer version, but Safari 5.1’s SunSpider score was roughly 7 percent faster than its predecessor’s. In general use, Safari 5.1 on Snow Leopard felt modestly snappier and more responsive than version 5.0.5, especially on dynamic sites using JavaScript and jQuery.


Safari 5.1 gives Apple’s browser enough horsepower to hold its own against rivals in day-to-day browsing. More importantly, its new features truly distinguish it from the pack, making Safari 5.1 a great step up from its predecessor.