Tired of leaking data across the web? Firefox and its privacy tools can help protect you and your data as you visit websites. Among the threats Mozilla's Firefox web browser for Windows and MacOS can protect you from are trackers that gather your browsing history, cryptominers that secretly use your device's resources to mine cryptocurrency and fingerprinters that uniquely identify you based on your device, settings and apps.
A fingerprinter is an especially stealthy tool that websites and advertisers use to build a specific profile of your online activities, using subtle hints your browser leaves on websites you visit. Factors include which browser you use, which extensions you've installed, your networking configuration, your device's time and your wireless settings. In essence, you've left your "fingerprints" all over your browsing activity.
Taken all together, these small bits of information can form a unique set of characteristics about you and your machine that can advertisers can use to identify your individual device and track you across the web without your permission.
Here's how to protect your privacy using Firefox's privacy and security settings.
How to use Firefox's content-blocking tools
Firefox 68 can protect you from websites that gather information about you without your consent as well as from cryptominers and fingerprinters. You can check which version of Firefox you're running by selecting About Firefox from the Firefox menu.
Because blocking trackers can also cause some sites to break, Firefox lets you choose among privacy settings to find a balance between protection and usability.
1. From the Firefox menu, choose Preferences. (You can also get here by clicking the hamburger menu on the right side of the toolbar and choosing Options on Windows and Preferences on MacOS.)
2. In the preferences window that opens, click Privacy & Security.
3. Choose which privacy setting you want to use:
- Standard protection blocks trackers in private windows and third-party tracking cookies.
- Strict protection to block trackers in all windows and third-party tracking cookies.
- Custom lets you fine-tune what you want to block, including cryptominers and fingerprinters. In an upcoming release, Mozilla will by default block cookies with third-party trackers, but you can turn on this enhanced tracking protection now if you want to check it out by turning on Cookies and then selecting "Third-party trackers" from the pop-up menu.
4. After you make your selection, a "Reload All Tabs" button will appear. Click it to apply your new tracking setting.
(If you're new to Firefox, Mozilla will turn on the enhanced tracking protection by default the first time you use the browser. For existing users, Mozilla will switch on the protection in the coming months.)
Note: You may want to tweak your privacy settings if you find that some of your favorite sites behave strangely after you block trackers.
You can also turn on Do Not Track here to signal to websites you don't want to be tracked, but sites don't have to honor your request, and in fact turning on Do Not Track can be one of the bits of information advertisers use to fingerprint your browser. If you want to take the next step in guarding your privacy, you can look at using a VPN and check which permissions you're giving apps.