How to control your data on Firefox

Increase your privacy in Firefox: How to set up Private Browsing mode or another customised browsing mode, clear your browser history, change your default search engine and install useful add-ons and extensions.

Last Updated: 20 Feb 2017

If you don't have Firefox already, you can download it here

Your browser is your main portal to the internet. It's necessary - but it also allows allows trackers to collect information about you.

Changing your default browser settings  (and then installing the right add-ons) will give you more more control over who has access to your data.

How to change your default privacy settings

Start here:

Firefox → Menu Icon Firefox (top right) → Preferences --> Privacy -->

Manual privacy setting Firefox


check Tell sites that I do not want to be tracked

Your browser will tell every website you visit that you do not want to be tracked.

Note: Websites are, unfortunately, not required to respect this message, but it can work quite well in combination with Privacy Badger, which is designed to automatically block trackers that ignore Do Not Track requests.



Private Browsing Mode  Private Browser Firefox

'Private Browsing' allows you to browse the Internet without Firefox saving any information in your browser history. You can set Private Browsing by default, or you can use it only occasionally.

Setting private browsing by default can be done in two ways:

1.  Firefox → Menu Icon FirefoxPreferencesPrivacyselect Never remember history

2. Firefox → Menu Icon FirefoxPreferencesPrivacyselect use custom settings for history --> check: Always use private browsing mode

When you close Firefox, the following will be cleared: your browser, search, web form and download histories, as well as cookies and temporary files.


  • What will be saved and what deleted is already pre-defined - you can't customize 'private browsing mode' to to suit your own needs.
  • Your history will only be cleared when you close the browser
  • The trackers in the websites you visit can still collect data about you, including your browser history.
  • Private browsing excludes the files you download and the pages you bookmark. These are saved.
  • Private Browsing doesn't make you anonymous on the internet.


Using 'Private Browsing' occasionally
'Private Browsing' mode can also be used for a single window:

Open Firefox → Menu Icon Firefox→ New Private Window


Customised Browsing

Maybe you don't want Firefox to delete everything every time you close the browser, as it does in  Private Browsing mode. You can customise your privacy settings yourself, to create your own default browsing 'mode' - deciding exactly what information will be deleted, and what saved, when you close the browser.

Firefox → Menu Icon FirefoxPreferences --> Privacy -->

History → select use custom settings for history  → uncheck: Always use private browsing mode

uncheck: Remember my browsing and download history 

uncheck: Remember search and form history

check: Accept cookies from sites --> Accept third-party cookies: select Never --> Keep until: select I close Firefox. (see more about these options, below)

check: Clear historChange Setting for Clearing History Manually Firefoxy when Firefox closes  → Click on settingscheck all the boxes that you do not want your browser to remember.  (see more about these options, below)

'Accept third-party cookies: Always / From visited / Never'

This allows you to choose whether to allow websites to set cookies in your browser.

Note:  If we choose the option 'Accept third-party cookies: Never' this might affect functionality of some websites, such as the login function. To enable these websites to work fully, click on exceptions and add the URL of the website to the list.


'Clear History when Firefox closes':

Clear History opens up an extended dialog box that allows you to decide exactly what is saved and what is deleted in your browser history when you close the browser.


  • As in Private Browsing mode, your history will only be cleared when you close the browser.
  • The trackers included the websites you visit can still collect data about you.
  • Clearing history does not make you anonymous on the Internet.


Location bar (the URL bar)

Location baruncheck History, Bookmarks and Open Tabs

When the boxes for History, Bookmarks and Open Tabs are checked, your browser not only stores in memory the websites you have visited, but also makes suggestions. For this kind of personalisation of your browser, Firefox needs to collect data about you. Unchecking these options means less data is collected.


Tips for further controlling your data

Change your default search engine

There are a number of good search engines out there that offer a lot more privacy than Google. Privacy-enhancing search engines like DuckDuckGo, Searx, StartPage or Ixquick, do not collect your data traces, which means that you can keep your search history private.

Firefox → Menu Icon FirefoxPreferences --> Searchselect DuckDuckGo or another search engine.

Clear your History regularly while browsing

Firefox → Menu Icon FirefoxHistory --> Clear recent history

It's good to regularly clear your browsing history. Even when you're in 'private browsing' mode, your history and cookies will not be deleted until you close the browser completely. In just one day you can build up quite a big history if you don't clear it as you go. 


Useful add-ons and other software

There are some very effective pieces of software you can install to block trackers, encrypt your website connections, stop spying ads from running. Go here for more.