Mercury Web Browser Pro for iPhone and iPad

Your iOS device comes with a mobile version Safari built right in. Why would you need a third-party browser like Mercury Web Browser Pro? Developer iLegendSoft’s answer to that question is simple: To fill the void of Safari’s missing features.

Mercury, a $1 app that’s optimized for the iPhone, iPod touch, and iPad, packs in a slew of options and niceties that Apple opted to leave out of Mobile Safari. The end result is that, in several tangible ways, Mercury feels closer to desktop Safari than its mobile namesake does.

Unlike the mobile edition of Safari, Mercury offers browser tabs, customizable themes, download and unzipping support, unique multitouch shortcuts, ad blocking, screen dimming, and more. I was most intrigued by the promise of tabbed browsing, so that’s what I checked out first.

And indeed, miracle of miracles, Mercury’s implementation of tabs is nothing short of excellent. In my testing on the iPad 2, Mercury could keep eight tabs open and in memory—meaning that when I switched from one tab to another, pages remained loaded, and didn’t need to be refreshed. The tab implementation feels remarkably close to how you’d expect Apple to handle it.

The tabs aren’t 100 percent of the way there, though. If I’m in a Mercury tab on Macworld.com, and then select the location bar to tap in Google.com and hit Return, the browser tab keeps showing “Macworld” as the title while Google loads, not changing the tab title until Google has rendered completely. I got used to it, I guess, but it’s still a bit disconcerting each time. Worse, if I go from Macworld.com (which has a favicon) to a site that doesn’t sport a favicon of its own, the new site erroneously inherits Macworld’s icon. Since tab title space gets increasingly cramped with each new tab you open, those icons can provide great visual cues—unless, of course, they’re attached to a page in error.

Still—there are tabs! On the iPad! And the experience really is great.

Mercury packs in plenty more features that Safari lacks. You can customize the theme; I prefer the default, Safari-esque view, but you can choose artsy themes, wood-paneled alternatives, and more. (Two themes, one called Christmas and another called Wood, cost $1 each as in-app purchases.) The browser also offers a full-screen browsing mode, but that’s one feature I never crave. I prefer the always-visible location bar, and the few extra pixels aren’t worth the hassle to me. That said, if fulls-creen browsing gets you going, Mercury’s implementation seems just fine to me.

The browser provides more sharing options than Safari. You can tap to share a given URL not just via e-mail, but also through Twitter and Facebook. A Private Browsing option keeps the URLs you visit out of Mercury’s History, and trashes all cookies when you exit the app, which I suppose could be useful if you a) visit unseemly sites and b) share your iPad with others.

Mercury can also download files. The app can save Web pages into a file manager, so that you can review them later, even if you’re online. Even better, the app can actually download files from the Internet, which also end up in that file manager. You can then transfer those files to your Mac via Wi-Fi through an in-app Web server that Mercury offers, or send them to Dropbox, e-mail them, or send them to other compatible iOS apps to open. You can run multiple downloads simultaneously, in the background, as you surf. It’s impressive, and another feature that’s implemented well enough that its omission from Safari seems odd.

The app also packs in a few features to help make reading easier—you can adjust font sizes, control brightness (separately from the iPad’s system-wide brightness control), and enable a very effective ad blocker. Mercury offers its own Bookmarks manager, and the developers provide instructions for importing your (desktop) Safari bookmarks, though there’s currently no way to keep them in sync automatically.

Of course, the Web rendering within Mercury is superb. That’s because it uses the same engine that Mobile Safari itself uses, with one notable exception: Because of how iOS 4.3 handles JavaScript, Mercury can’t avail itself of the speed-ups the Safari browser gets. Running the WebKit SunSpider JavaScript performance test took more than twice as long in Mercury compared to the mobile version of Safari in my experimentation.

That’s the biggest knock against Mercury, and it’s not the developer’s fault. But even if JavaScript takes a bit longer to execute, Mercury tends to feel faster than Safari. Tabbed browsing makes managing my Web surfing experience much more efficient, and I didn’t realize how much I longed for the ability to download files to my iPad until Mercury offered it.

The free lite version limits you to two tabs, and displays ever-present ads. Honestly, though, you don’t need to waste your time trying that version out. Trust that the $1 you’ll spend on the Pro version of Mercury is money very well spent for any frequent iPad surfer.

[Lex Friedman is a frequent contributor to Macworld.]