Terms & Conditions: Firefox’s privacy policy is big, but not scary

Firefox privacy policy explained

What are you really agreeing to when you click that fateful “agree button? Terms & Conditions cuts out the legal lingo to spell it out in plain English.

If you ask any “in the know” Web users, there are really only two browsers to choose from: Chrome or Firefox. (Yes, Internet Explorer is the most-used browser in the U.S., but that’s mostly due to its default status on the most-used operating system: Windows.) While Chrome has been on the rise, having jumped past IE as the most-used browser in the world earlier this year, Mozilla’s Firefox remains a solid third, according to StatCounter, with approximately 450 million users worldwide.

And yet, we would guess the number of people who’ve read the Firefox privacy policy is much closer to zero — which is a shame, because it’s quite well done. Let’s take a look at the few bits of info that every Firefox user should know.

Firefox Privacy Policy

Like all browsers, Firefox is literally the connection between your computer and the Internet at large. That said, Firefox is only legally responsible for a very small amount of the data that is transferred from you to the websites you visit. And it is the privacy policies and terms of service for each and every website you visit that you really need to worry about.

This is especially true because Mozilla is extremely careful to explain when and what data are transferred from your copy of Firefox to Mozilla. I really wish all companies were required to be as clear and thorough as Firefox is. The only downside to this is how long it ends up being as a result. So here is the most condensed version possible.

Data collection

Firefox itself transmits only a limited amount of data to websites (which may or may not include other tracking or data-collection mechanisms themselves). This “non-persona” and “potentially personal” data includes: IP address (which is linked to location data), device type, referring website (the site you visited before going to another site), and language preferences.

This data is simply what is conveyed to other websites. Mozilla itself “does not collect or track any Personal Information or any information about the websites you visit, and Mozilla does not release the raw information we obtain from these Firefox features to the public.”


Firefox automatically checks to see which add-ons you have installed as a way to keep you up-to-date on updates. If this features annoys or worries you, follow these instructions to turn it off.

Also, Firefox will check once a day to see if any of the add-ons you have installed are problematic for whatever reason (e.g. they pose a security risk). All bad add-ons end up on the Blocklist. Mozilla does not offer a simply way to turn off the Blocklist feature. But if your browser making a connection with Mozilla’s servers freaks you out, you can see how to disable it here. (Warning: Doing so is extremely complicated, and probably not worth your time.)


Firefox Syn

Firefox Sync is a feature that started with Firefox 4, and has been available in every version since. As the name implies, Sync allows you to — you guessed it — sync your Firefox history, bookmarks, and other settings between different computers. Mozilla says explicitly that none of this information is transmitted in a readable format, so don’t worry about Mozilla finding out which porn websites you’ve saved. Mozilla only saves the number of bookmarks you have, and the number of websites in your history — not what they actually are.


All versions of Firefox mobile include the Location-Aware feature, which allows websites to access your geographic location in order to serve you location-specific advertising and services. Firefox will ask each time if you want to share your location data when you visit a website that wants to access it. If you say no, your location remains secret.

If you do allow Location-Aware, Mozilla requires that all third-parties that access this data through Firefox keep the data out of public view. Any personal or potentially personal data (like IP address) third-parties collect may only be used to provide the service they are offering. If third parties want to use your data for something else, they have to strip all the personal data out.


Firefox implements a number of highly technical security features to help keep your computer protected from the big bad Web, including checking security certificates and scanning for URLs that may contain malicious code. If Firefox does detect such a site, it will store a bit of information about the URL on your hard drive, which can then be accessed for comparison against other URLs you visit, so just heads up that that’s happening.

That said, Firefox should not be your last line of defense against viruses and phishing attacks — you’re much better off with a robust anti-virus program.

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