Mozilla on Tuesday released Firefox Quantum, and even if you long ago switched to Google Chrome, it's worth giving the browser upgrade a spin.

Why? First and foremost, version 57 of the open-source browser is faster, clocking in at twice the speed of Firefox 52 from March, according to the Speedometer 2.0 benchmark. Mozilla knows Chrome won many of us over with performance, but after months testing it, I can affirm Firefox 57 delivers its promised big bang.

(ZDNet, a CNET sister site, also found that Firefox Quantum delivered on speed.)

Mozilla

Second, Firefox has an important role to play if you care about the value of the web as neutral tech territory -- a place free of the control Apple and Google exert over our phones and the apps we can run on them. Mozilla's mission is to keep the web open and competitive, and Firefox is how Mozilla works to endow the web with new technology like easier payments, virtual reality and fast WebAssembly-powered games.

"Their mission is a good one and does keep pressure up to keep the web open," Gartner analyst David Smith said. He recommended web surfers use "multiple modern browsers."

Mozilla famously undermined the dominance of Microsoft's Internet Explorer when it launched Firefox 1.0 in 2004. But since that triumph, its fortunes have faded. Google's Chrome is now the most-used browser by far, and Mozilla has largely been sidelined when it comes to phones and tablets. Firefox Quantum, a complete overhaul of the browser that took more than a year's work to achieve, is an attempt to start fresh.

"We pulled ourselves up to and in some cases ahead of Chrome," said Mark Mayo, Mozilla's senior vice president of Firefox. "We doubled the performance of Firefox this year. The tentative goal is can we double it again in 2018."

Riding a 'huge upswing'



Even if Mozilla delivers that kind of speed boost, success won't be easy because it's hard to get people to change browsers. Firefox accounts for 6 percent of browser usage today compared with 55 percent for Chrome and 15 percent for Apple's Safari. Narrowing it just to personal computers -- Mozilla's primary focus for the Quantum upgrade -- Firefox has 13 percent to Chrome's 64 percent.

Screenshot by Stephen Shankland/CNET

But Mozilla has some grounds for optimism. Usage of Firefox Developer Edition, targeted at web programmers, more than doubled after it was updated to the Firefox 57 version in September. Usage of Firefox Nightly version, a less-stable test version, has nearly tripled in a half year. And social media chatter, while far from an infallible predictor, shows a "huge upswing" in favorable views, Mayo said.

"It's the biggest jump in sustained upswing in sentiment since I've been here," Mayo, who's been with Mozilla for a half a decade, said. That could translate to better market share, he said, though likely not for a few months.

Mozilla says improvements over the last year have stopped defections to other browsers, with about 100 million of us now using Firefox daily. What remains to be seen is whether Mozilla can turn its new performance into more users and thus more leverage to pursue its mission.

What Quantum means for you

Key to Firefox 57's improvements is a project called Quantum that overhauls just about everything the browser does between when it ingests website code and splashes the resulting pixels onto your screen. Quantum, after which Firefox Quantum is named, actually delivered some improvements in the summer, and another big part, called WebRender or Quantum Render, should arrive in early 2018.

Enlarge Image Mozilla

It was risky to change so much of Firefox's software, and Mayo speaks with relief that the overhaul went as smoothly as it did.

"Everything major we wanted to get in made it. ... It's almost certainly the biggest refactoring ever done in software engineering, at least in public," Mayo said of the overhaul. "Seventy-five percent of the code base had to be touched. Almost 5 million lines of code were impacted."

For ordinary folks, the result is a browser that's snappier to respond, loads websites faster and sports a new look. The Photon project sweeps away Firefox's swoopy tabs and replaces them with plain-vanilla rectangles that, while not as distinctive, aren't sluggish to draw and handle. Photon also brings a new "page actions" menu within the address bar and eliminates the previously separate box for initiating web searches.

In addition, three years into a five-year deal to use Yahoo's search engine by default in the US when performing searches from Firefox, the nonprofit organization said it's gone back to Google in the US and Canada.

Mozilla ended the Yahoo search default, though it thinks there are other possibilities to work with Verizon, which acquired Yahoo in June. "We exercised our contractual right to terminate our agreement with Yahoo based on a number of factors including doing what's best for our brand, our effort to provide quality web search, and the broader content experience for our users," Mozilla Chief Business and Legal Officer Denelle Dixon said in a statement.

You'll also see a simplified logo with richer colors, a new tool to take screenshots and share them on the web, and integration with the Pocket bookmarking service Mozilla uses to recommend sites you might be interested in.

If you customize Firefox with a lot of extensions, though, you might see problems. Firefox Quantum jettisons the pioneering add-on framework Mozilla introduced 13 years ago in favor of one based on Chrome's extension technology. Most of the top 100 extension are updated, but some people will suffer, Mayo said.

"There are some people's workflows that are going to stop working. This is always super painful," he said. One bridge to the future if you're on that list: Try the slower-moving Firefox ESR version, which will support older extensions a bit longer.

What lies ahead



The new Firefox also lays the technological foundation for new improvements. The Quantum Render project should arrive in Firefox 59, which just entered testing through the Nightly channel. Quantum Render, like the Quantum CSS (aka Stylo) project that arrived in Firefox 57, draws from Mozilla's experimental browser project called Servo.

And the new Firefox architecture uncorks bottlenecks so Mozilla can do things like load the parts of websites you want first, after which the ads trickle in at a lower priority, Mayo said.

Then there are just lots of little speed boosts on the way, like storing JavaScript programming instructions more cleverly so Facebook loads a tenth of a second faster.

"What we've shown is you don't need to be one of the Frightful Five" -- Apple, Google, Amazon, Microsoft and Facebook -- "to build software. People like that story. They want to believe it," Mayo said. "At some level, everyone likes the David versus Goliath, little guy versus big guy thing."

First published Nov. 14, 6 a.m. PT.

Updates, 10:13 a.m, 12:39 p.m.: Adds details about Mozilla switching Firefox back to Google search by default in the US and Canada.

First published Nov. 15, 4:09 p.m. PT.

Update, Nov. 16, 12:19 p.m.: Adds link to ZDNet story on Quantum.

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