Mozilla’s Firefox web browser could soon block sites and services from bounce tracking Firefox users to improve privacy.
Bounce tracking is a widely used form of tracking that redirects requests. This form of tracking happens in the background, which means that users are usually not aware of it.
Here is an example. A click on Link A should lead to Destination B. With bounce tracking, Bounce C is added, so that the request goes through Bounce C before it reaches the destination.
- Without: Link A > Destination B
- With: Link A > Bounce C > Destination B
There can be multiple bounces. With a bounce server involved in the loading process, users can be identified by the operators of the bounce server.
The W3C Community Group Draft report defines Bounce Tracking in the following way:
Bounce tracking refers to the use of redirects in a top-level context (including HTTP 3xx statuses, meta elements with http-equiv=refresh attributes, and script-directed navigation that doesn’t wait for user input) along with link decoration to join user identities between sites.
Bounce Tracking Protection in Firefox
Mozilla is testing the new privacy feature in Firefox Nightly currently. It runs in dry-run mode currently, which means that it is not blocking, but only reporting.
The data that is collected during the dry run helps Mozilla test and optimize the feature.
It will be enabled fully in Firefox Nightly before it lands in Firefox Stable eventually.
Not the first browser to implement the privacy feature
Mozilla is not the first web browser developer that is adding bounce tracking protection to a browser.
Brave Software introduced the feature back in October 2021 in Brave Nightly. It is now available in Brave Stable and was improved in 2022 with a feature that Brave Software called Unlinkable Bouncing.
This feature reduces the effectiveness of bounce tracking further through the use of temporary DOM storage.
Google’s Chrome browser supports bounce tracking mitigations as well, but only if third-party cookies are blocked in the browser according to this webpage.
Closing Words
Mozilla may be a little bit late to the party, but this is still a welcome privacy addition to Firefox. There is no ETA yet for the integration in Firefox Stable. Provided that tests are successful, it is likely that the feature lands in Firefox later this year.
With the new interim CEO in charge, Mozilla has launched several user-friendly features in Firefox or is working on integrating them.
Have you tried Firefox recently?