Browser makers have focused their attention on the feature that matters most to Web surfers, other than not crashing: speed.

Apple’s Safari 5 browser, launched yesterday in the shadow of Steve Jobs’ new iPhone, is said by Apple to run JavaScript programs embedded in Web pages 30 times faster than its predecessor. That puts it in the same league as Chrome and Firefox. (Apple claims Safari is faster than these browsers, but it seems every browser comes out tops in its maker’s lab tests.)

I don’t trust myself to run definitive benchmark tests, but Safari 5 definitely loads VentureBeat’s busy pages faster than Chrome, which had seemed fast to me before. The new Safari also pre-loads the Internet addresses of sites linked from whatever page you’re looking at. That can save a few seconds when you click, depending on how slow your network is at DNS lookups.

Microsoft’s Internet Explorer 9 development team, currently engineering the next version of Windows’ built-in browser,  made a competition video that shows the still-in-development IE9 also speeding through interactive Web content. Microsoft’s video, not surprisingly, makes IE9 seem even faster than Safari.

How did speed come to be king? Google’s Chrome browser seems to have tweaked the noses of the engineers who build Firefox, Safari, Opera and Internet Explorer. Rather than adding more buttons and toolbars onto Chrome’s face, Google stripped down the graphical user interface knobs and cranked up the speed at which Chrome loads and displays modern Web pages. Now, Apple and Microsoft are competing to speed up their own browsers enough that users will immediately notice.

What matters to everyday Web users is that browser makers have realized that it’s more important to load pages quickly, and respond snappily to interaction by the user, than to pile on more features. Chrome’s rapid rise in use among early adopters suggests that a browser that makes a computer feel fast will steal customers from one that gets bogged down, regardless of what other features it does or doesn’t have.

The return to speed is a boon to the entire Internet economy. Google tests have shown that if a page loads faster, people will hit it more often. That’s good for e-commerce sites and social networks, which make more money if people visit more often and click around more while there. By putting their time into speeding up their browsers, Apple, Microsoft and everyone else are giving us all back a chunk of our own lives, even if it’s done 400 milliseconds at a time.