Chrome and Firefox borrow the performance features

Chrome & Firefox

Chrome to get Firefox caching back / forward, and Chrome to get Chrome unloaded tab unused.

As part of ongoing efforts to improve the speed and reliability of their projects, the Google Chrome and Firefox teams are both borrowing features from each other’s browsers.

This focus on improving browser performance has become a major concern for both browser projects, as both Chrome and Firefox have been characterized as slow and resource hungry in recent years.

The Chrome team was the first to announce a new performance-enhancing feature when it revealed plans for what the company’s engineers call “back / forward cache”— or bfcache last week.

This feature, which has been present for years in Firefox and Safari, works by storing for longer periods of time copies of the user’s recently visited web pages in browser memory. If the user chooses to go back and forth through the sites recently visited, these pages will be loaded from the memory (cache) of Chrome instead of being reloaded from scratch.

“Think of it as pausing a page when you leave and playing it when you come back,” said Google Chrome engineer Addy Osmani. “We estimate that this change could improve the performance of up to 19 percent of all mobile Chrome navigations.” There’s no precise timeline for bfcache landing in the main Chrome version.

Work on the feature began last month, Google also published a design document. Similarly, Firefox has also plunged into Chrome’s feature set for its upgrade-set to land with Firefox 67, scheduled to be released in May. Firefox’s new feature will automatically unload old and unused tabs from Firefox’s memory, saving RAM.

In Firefox Nightly versions, the feature is already live where it is enabled by default. According to an entry on Mozilla’s bug tracker, Firefox will first unload regular tabs, then pinned ones, regular tabs that play audio content, and finally pinned audio tabs.

Implementation of Firefox is inspired by a Chrome feature called Automatic Tab Discarding that Google shipped four years ago in 2015 with its browser. The feature is also enabled in Chrome by default, and by accessing chrome:/flags/#automatic-tab-discarding, users can turn it off.

Mozilla’s bug tracker, Firefox will first unload regular tabs, then pinned ones, regular tabs that play audio content, and finally pinned audio tabs.In Firefox Nightly versions, the feature is already live where it is enabled by default. According to an entry on

Implementation of Firefox is inspired by a Chrome feature called Automatic Tab Discarding that Google shipped four years ago in 2015 with its browser. The feature is also enabled in Chrome by default, and by accessing chrome:/flags/#automatic-tab-discarding, users can turn it off.

Mark Funk
Mark Funk is an experienced information security specialist who works with enterprises to mature and improve their enterprise security programs. Previously, he worked as a security news reporter.