Mozilla Firefox 77 Nightly version has received a new option in the Custom mode for Enhanced Tracking Protection in Privacy and Security Settings to let users enable the ” Dynamic First party isolation” feature in the Firefox browser, the feature can also be enabled by changing a preference value in about: config.
Beginning with Firefox 53, Mozilla has hidden the first party isolation feature behind a preference called privacy.
Till now custom setting allows blocking these types of cookies in Firefox browser
- Cross-site and social media trackers
- Cookies from unvisited websites
- All third-party cookies
- All cookies.
In addition to the above, custom setting for Enhanced Tracking Protection in Firefox Nightly offers another new option for cookies in the dropdown:
cross-site and social media trackers, and isolate remaining cookies
Choosing this option may cause certain websites to break where you may not able to sign into them. The Dynamic FPI can also be enabled by changing the following preference in about:config to 5.
Enable Dynamic First Party Isolation in Firefox
To test the feature, launch Firefox Nightly
1. Click on menu, select Options
2. Privacy & Security > Custom,
3. Select “Cross-site and social media trackers, and isolate remaining cookies”
You need to reload all tabs or you can restart the browser for the same.
When you select the option, Firefox Nightly shows a warning at the bottom alerting you that “blocking trackers and isolating cookies could impact the functionality of some sites”.