How to force Firefox to forget your browser history (TechRepublic) Watch Now

Video: How to force Firefox to forget your browser history (TechRepublic)

Firefox 59 will reduce how much information websites pass on about visitors in an attempt to improve privacy for users of its private browsing mode.

When you click a link in your browser to navigate to a new site, the site you go on to visit receives the address of the site you came from, via the so-called "referrer value".

While this helps websites understand where visitors are coming from, it can also leak data about the individual browsing, because it tells the site the exact page you were looking at when you clicked the link, said Mozilla.

Browsers also send a referrer value when requesting other details like ads, or other social media snippets integrated in a modern website, which means these embedded content features also know exactly what page you're visiting. Sites record this referrer data and some sell it on to allow site visitors to be targeted with ads.

In some cases, that referrer can leak highly sensitive information. Researchers at the Electronic Frontier Foundation previously found one referrer from healthcare.gov also passed on data about the age and zip code of the user, along with whether they were a smoker or not, and their income.

To prevent this type of data leakage, from Firefox 59, the private browsing option will remove path information from referrer values sent to third parties, effectively stripping out additional data and only leaving the web domain.

Download now: Encryption policy

"This change prevents site authors from accidentally leaking user data to third parties when their users choose private browsing mode," said Mozilla privacy engineer Luke Crouch.

Users can also change their default referrer options in Firefox. These will override the browser's default referrer policy and override the site author's referrer policy, putting the users choice first.

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