Firefox Fast & Private Browser

"We also work with advertising providers to deliver relevant sponsored content using programmatic technologies. To support this, we may share limited, non-identifying information — such as device type, IP-derived location information, and category of content viewed — to help determine which ads to display. ... This data may be shared with our advertising partners on an aggregated and/or de-identified basis."

Mozilla shares device type, location, content categories, and interaction data with advertising partners and marketing partners to serve ads and measure campaigns, even if de-identified or aggregated.

"We infer your location from your IP address at the level of your country, city, or region. ... Mozilla collects technical and interaction data, such as the position, size, views and clicks on New Tab content or ads, to understand how people are interacting with our content and to personalize future content, including sponsored content."

Mozilla routinely derives location from IP addresses across many features including search suggestions, New Tab content, advertising, and marketing — this location data is also shared with advertising partners.

"In some regions, we use this data to build models and group users based on common attributes. These groupings help us understand how people are interacting with our content and to personalize future content, including sponsored content. We use on-device processing and OHTTP to avoid revealing to Mozilla the attributes of any specific user."

Mozilla builds user attribute models and groups users into segments for personalized content and advertising, though they use privacy-preserving technologies to limit direct identification.

"In general, we do not retain personal data for more than 25 months, but actual retention periods may vary depending on the type of data and the purpose(s) for which it was collected (for example, we retain your "first seen" date for the period of your use of Firefox, so we know how long you've been a Firefox user). ... We may also retain data for extended periods of time on a de-identified or aggregated basis."

While Mozilla states a general 25-month limit, retention periods can vary by data type, some data is kept for the entire duration of Firefox use, and de-identified data may be retained indefinitely.

"We may need to change this policy and our notices, in which case the updates will be posted online and we will update the effective date of this notice. If the changes are substantive, we will also announce the update more prominently through Mozilla's usual channels for such announcements, such as blog posts and forums."

Mozilla can change the privacy policy at any time by posting updates online. While substantive changes get blog/forum announcements, there is no requirement for user consent or opt-in to continue using the service under new terms.