Mozilla Releases Multi-Process Firefox Upgrade


It may have taken eight years to get here, but Mozilla has finally released a version of Firefox with the multiple process technology available in other popular web browsers. Dubbed Firefox 54, Mozilla claims it is the fastest browser it has ever released, and outperforms Chrome when it comes to speed and resource consumption.

Previous versions of Firefox used a single process to run multiple tabs in a browser, unlike browsers, such as Chrome, Safari, and Edge, which use several independent processes. That meant that having a single tab open to a complex Web page running animations or doing some other complex task could slow down all of the other open tabs.

Divide and Conquer

That problem has become more acute for users over time, as the complexity of the average Web page continues to increase. The average Web site today contains 2.5 MB of data. Mozilla’s solution is to split the workload into as many as four separate processes all running Web page content across open tabs.

The company is calling the change in architecture, which it described as the single most significant change in the Firefox code in its history, “Electrolysis.”

“With today’s release, Firefox uses up to four processes to run web page content across all open tabs. This means that a heavy, complex web page in one tab has a much lower impact on the responsiveness and speed in other tabs,” Mozilla said in a statement today. “By separating the tabs into separate processes, we make better use of the hardware on your computer, so Firefox can deliver you more of the web you love, with less waiting.”

Shorter Pipeline for Future Upgrades

Mozilla said the new version of Firefox runs faster and crashes less than previous versions, particularly on systems with less RAM. The company said it tried to strike a balance between speed and resource usage by limiting the number of independent processes that run. That allows it to use less RAM than other popular browsers on Windows, Linux, and macOS, the company said.

In addition to the upgrade, Mozilla announced that it has also substantially shortened its pipeline for releasing new features from four stages to three. In theory, that should help accelerate the pace at which the company is able to introduce new features to the browser in the future.

Firefox was once securely established in second place as the most popular browser behind Internet Explorer until Chrome overcame it in 2011. The open source browser still lags behind both, but remains ahead of Apple’s Safari and Microsoft’s Edge browser.

The company said it also plans to roll out several additional improvements to the browser over the course of the year as part of its Quantum project to allow Firefox to make more efficient use of GPUs and modern multi-core CPUs.