Firefox 90 introduces the next version of SmartBlock, a browser tracking blocking mechanism built into private browsing and tight spaces, which now includes improvements to prevent buttons that allow you to log in to websites using your Facebook account from breaking, Mozilla announced Tuesday.
SmartBlock was first introduced with Firefox 87 in March, and if you’re not familiar with it, here’s a Mozilla description of how it works, company blog:
SmartBlock intelligently repairs websites that violate our tracking privacy without compromising user privacy.
SmartBlock does this by providing local stand-ins for blocked third-party tracking codes. These stand-in scripts behave only enough like the originals to ensure that the website works properly. They allow broken sites that rely on the original scripts to load their operations intact.
Sometimes, however, the feature breaks the Facebook login buttons. In a new blog post, Mozilla’s Tom Wisniewski and Arthur Edelstein explain why this would happen, using an example of trying to log on to Etsy.
“If you used before Firefox 90, if you used the Private Browsing window when you clicked the Continue Facebook button to sign in,‘ signing in ’failed because the required third-party Facebook script was blocked through Firefox,” they write.
However, with Firefox 90 and SmartBlock 2.0, you need to be able to use all of Facebook’s login buttons, while SmartBlock 2.0 still prevents cross-site tracking. In the updated browser, “all Facebook scripts will be blocked initially, as before, ensuring your privacy is maintained,” they write. “But when you click the ‘Continue with Facebook’ button to sign in, SmartBlock responds by quickly unblocking the Facebook sign-in script just in time to ensure a smooth sign-in.”
Firefox 90 will launch on Tuesday.