Mozilla today released Firefox 65 for Windows, macOS and Linux and called out new user controls for setting the desired level of anti-ad tracking by the browser.
Developers also patched seven vulnerabilities, three tagged as "Critical," Mozilla's highest threat ranking. "This results in the stream parser object being freed while still in use, leading to a potentially exploitable crash," Mozilla said, referring to a "use-after-free" bug in the browser.
Firefox 65, which can be downloaded from Mozilla's site, updates in the background, so most users need only relaunch the browser to get the latest version. To manually update, pull up the menu under the three horizontal bars at the upper right, then click the help icon (the question mark within a circle). Choose "About Firefox." The resulting page shows that the browser is either up to date or explains the refresh process.
Mozilla updates Firefox every six to eight weeks; the last time it upgraded the browser, to version 64, was Dec. 11.
Anti-ad tracking stays off by default
Mozilla's most ambitious initiative for Firefox last year was the introduction of "Enhanced Tracking Protection," its name for blocking cross-site tracking, the page-embedded trackers that sites or ad networks use to follow users around the web. The October debut of the feature was touted by Mozilla as a more surgical version of the broader content blocking that had broken some websites and caused confusion.
Enhanced Tracking Protection was off by default in Firefox 63, but Mozilla said that it would be switched on as of early 2019, implying that meant with Firefox 65.
"Before we roll this feature out by default, we plan to run a few more experiments and users can expect to hear more from us about it," Nick Nguyen, Mozilla's vice president of product strategy, wrote in a Jan. 29 post to a company blog.
Instead, Firefox 65 sports a revamped settings section dubbed "Content Blocking." Nguyen said the redesigned settings were prompted by additional testing.
The section is more visible and included more information about the impact of switching tracking protection on. To do that, users have to select Options (Windows) or Preferences (macOS) from the menu under the three horizontal bars at the upper right, click "Privacy & Security" in the sidebar at the left, and then under the section labeled "Content Blocking," select the radio button marked "Strict."
A "Custom" radio button is also available for users who want to, say, block ad trackers but not cookies, or vice versa.
More information about Content Blocking can be found on the support website dedicated to Firefox.
Redesigned Task Manager
Firefox 65's other prominent addition is to the Task Manager page, displayed after entering about:performance in the address bar. The manager reports on memory and energy (read, battery) usage for each tab and add-on, then offers a quick way for users to close a gluttonous tab or disable a misbehaving extension.
The Windows version of Firefox 64 also now supports AV1 video compression, a royalty-free standard backed by a group - Alliance for Open Media (AOMedia) - whose members include Mozilla, Amazon, Apple, Facebook, Google, Intel, Microsoft, Netflix and others. David Bryant, a Mozilla Fellow who leads the organization's Emerging Technologies team, spelled out AC1 and Firefox's support in a separate post on Medium.com.
"We think someone's ability to participate in online video shouldn't be dependent on the size of their checkbook," Bryant said.
The next upgrade, Firefox 66, should reach users on March 19, according to the browser's release calendar.