This week, Mozilla launched Firefox 57—aka Quantum—the biggest update to the browser in its 13 year history. 75% of Firefox’s code has been rewritten for Quantum, 5,000,000 lines of code in total. 700 developers, including 80 volunteers, have contributed to the codebase since August. It is, in effect, a brand new browser. Firefox has always been a cool browser. Open-source credentials and a confirmed underdog status make it the first choice for those who prefer not to use their OS’ default. The latest stats put Firefox’s global share to around 6%, compared to Safari’s (combined MacOS and iOS versions) 15%, and Chrome’s 55%. Despite much affection for Firefox, there hasn’t been a compelling reason to make the switch, until Firefox Quantum.

Quantum Speed

I don’t recall when a new version of a browser was met with so much excitement, and it’s almost entirely down to one thing, Firefox Quantum goes like a rocket. [pullquote]Firefox Quantum goes like a rocket[/pullquote] Every browser makes the claim to have improved render speed, usually by a single-digit percentage. Firefox Quantum is twice as fast as the previous version of Firefox. However, that feels like an understatement; Firefox Quantum is perceptibly faster than any other browser on my machine, notably it’s substantially faster than Chrome. Browsing in Firefox Quantum feels like the whole web has been pre-cached. Mozilla’s own tests found that the beta release of Firefox Quantum was at least as fast as Chrome, but wasn’t substantially faster. They feel they closed the gap on Chrome, without exceeding it. They’re being modest. Anecdotally, my experience in the last couple of days is that Firefox Quantum is substantially faster across the board; it’s possible that I’m simply browsing sites that favor Firefox’s approach, like Google Search for example. What’s undeniable is that Firefox’s new found speed delivers an enjoyable browsing experience.

Quantum Efficiency

One of the ways Mozilla turbo-charged Firefox Quantum is changing the way it makes use of modern hardware. Complex software makes use of multiple processor cores by allocating different tasks to different cores to speed up processes. Developing in this way is complex, because if two cores are working on related tasks, one can easily override the other, introducing bugs to the system. This complexity is often solved by ring-fencing tasks, for example, allocating a CSS engine to a single core; less efficient, but more stable. Firefox Quantum has taken a leap forward by leveraging multiple cores for single tasks, or rather by subdividing tasks into smaller bite-sized chunks so that they can be distributed to more cores. One of the key components of Firefox Quantum’s speed is the new CSS rendering engine, Stylo. Stylo extends the multi-core approach by allocating different parts of the DOM rendering to different cores. According to Mozilla, Firefox Quantum uses 30% less memory than “the competition” (aka Chrome) on Windows. Digg’s testing found that Chrome used 40% more RAM and three times more processes than Firefox Quantum. [pullquote]What’s cool about Firefox Quantum is that the more cores you have, the faster it renders[/pullquote] What’s cool about Firefox Quantum is that the more cores you have, the faster it renders. Firefox is fast now, and it will only get faster in future. To make Quantum so efficient, Mozilla studied how people actually use the web. As a result, Firefox Quantum prioritizes tasks, for example a button interaction takes priority over something like caching, or garbage collection. This is a direction Mozilla intend to focus on in future releases. One of the most obvious benefits of prioritizing tasks is tabbing. Firefox Quantum uses less memory for multiple tabs than Chrome. Conducting research, with multiple tabs open, makes Firefox a no-brainer for me. In Quantum, your active tab is prioritzed over all other tabs, making the best use of resources. Which makes me wonder: Why weren’t browsers doing this before? It’s so obvious.

Mozilla Photon

Firefox Quantum’s UI will probably look a little different to you, especially if you’re upgrading from an earlier version of Firefox. Mozilla have taken a leaf out of Google’s book and developed their own design system for their Products, named Photon. While there’s no suggestion of Mozilla pushing Photon as a cookie-cutter approach to all design problems—as Google have with Material Design—it’s a pleasingly coherent approach that Mozilla previously lacked. Photon, in Mozilla’s own words, aims to be adaptable, quick, aware, approachable, supportive, and whimsical. Firefox Quantum’s UI ticks all of those boxes. There’s a greater attention to detail than we’ve seen in earlier versions of Firefox. For example, the nice subtle hover animation on inactive tabs. It all combines to be an enjoyable experience that is happy to fade into the background—which is precisely what a browser should be. There’s a couple of let-downs. I’m not thrilled that the blank tab has three separate search options: the browser location field, the search field, and the blank page search field. These are minor gripes in an otherwise great product.

The Verdict

There’s no question that Firefox Quantum is going to pick up market share. By this time next year it will have 15% of the market, still less than a third of Chrome’s user-base, but numbers that Opera would kill for. [pullquote]By any reasonable criteria Firefox Quantum is the best browser currently available[/pullquote] I switched to Firefox Quantum out of curiosity, fully expecting to switch back to Chrome in a few days; Chrome is now gone from my dock, and Firefox is set as my default browser. Admittedly Firefox Quantum has some extension compatibility issues, but that’s the case for any new browser and developers are already catching up. And I felt an unexpected pang of remorse when I finally bit the bullet and removed Firebug. By any reasonable criteria Firefox Quantum is the best browser currently available. Whether it remains so depends on the competition, and future Firefox enhancements—all indications are that Mozilla are determined to keep pushing the envelope. Firefox Quantum is a fast, resource-friendly, intelligently designed product. Browsing in Firefox is simply a more enjoyable experience, what more could you ask?