Mozilla Firefox was introduced into the world in 2004 and over time has found itself having to be modernised. One part of its modernisation is Project Quantum which involves writing parts of the web browser in Rust. As part of Project Quantum, the overall responsiveness of the browser is expected to be positively impacted thanks to a subproject called Quantum Flow.
Under Quantum Flow, work is being done to bring the overall cost of unloaded tabs as close to zero as possible. Dietrich Ayala, a developer working for Mozilla, had a look at just how much of an improvement Quantum Flow will deliver, and it’s staggering. In his tests he took a few versions of Firefox and measured how long it took the browser to start up with his 1691 open tabs, Firefox 51 ranked the worst as it took over seven minutes to load up.
With the inclusion of Quantum Flow in Firefox 55, Ayala saw his start up time slashed to a mere 15 seconds – 30 times quicker than what Firefox 51 could achieve. On the flip side, Firefox 20 opened the tabs in just over a minute and gradually right up to Firefox 51 the opening time became worse and worse. Quantum Flow will get rid of all of these regressions that have built up since April 2nd, 2013 when Firefox 20 was released.
Memory utilisation has also been drastically improved with Quantum Flow. With 1691 open tabs (with web pages unloaded, see lazy tabs) Firefox 55 uses just under 500MB of RAM. This is down from previous versions of Firefox going back to Firefox 30 which generally used about 2GB of RAM.
All of these improvements are putting Firefox on par with Google Chrome, on a technical level. One of the common criticisms levelled against Chrome is that it is a resource hog; Quantum Flow will only serve to drastically improve the situation for Mozilla.