What doesn’t incognito mode protect against?

Incognito windows (called Private Browsing in Firefox) are a great feature of modern browsers that will help you avoid some low-level tracking techniques. However, they are not an anonymity tool.
What does incognito mode actually protect against?

Among many other techniques, websites can use cookies to track your browsing history, which may also reveal your online habits.

Beyond the use of cookies, you may be tracked through DNS records or by your system administrator. An incognito window will help against some threats but is useless against others.

Almost all browsers have a private browsing window, but incognito mode on Chrome is perhaps the most well known.

What is incognito mode on Chrome?

Incognito mode on Chrome is a new window that will not save your browsing history, searches, or any cookies you pick up. When you close the incognito window, the session is gone for good.

How to go incognito on Chrome

  1. Click the three dots in the top right of the Chrome browser
  2. Select New incognito window from the dropdown

Alternatively, open incognito mode on Chrome with the shortcut Ctrl+Shift+N.

Browse privately with other browsers

Private browsing in Safari

In the Safari app, select File > New Private Window.

Private browsing with FireFox

  1. Click on the three horizontal lines in the top right corner
  2. Select New Private Window from the dropdown

Alternatively, Firefox Private Browsing can be opened with the shortcut Ctrl+Shift+P.

Does incognito mode hide your IP address?

No, it does not. Try a VPN or the Tor browser if you want to hide your IP address.

Is incognito mode really incognito?

An incognito window or private browser will open a new window that behaves like a freshly installed browser on a new computer. There are no plug-ins, no cookies, no bookmarks, no saved searches, and no pre-filled forms. Every time you close the incognito window, all the information the browser collected will be deleted.

Though it might be great for hiding you browsing history, unfortunately, incognito mode does not stop others from collecting information about you. Here are a few things that incognito mode will protect against, and some that it definitely does not:


Incognito mode will prevent cookies from identifying you

When you visit a website, embedded scripts will place a small file called a cookie on your computer. This cookie can, when you visit the site again, be read by the site and used to identify you.

This can be useful, as it allows you to stay logged in even after your computer is rebooted, and quickly lets you share news on any social media accounts.

However, cookies also let social media companies (and the NSA) track you across sites. For example, social media sites let news organizations embed snippets of code that show how often an article has been shared.

These snippets also feedback information about which sites you’ve visited, and which articles you’ve been reading. This gathered data can be used to feed you targeted advertisements or identify your religious, political, or sexual preferences.

How to stop cookies tracking you

  1. Disable third-party cookies and consider deleting cookies every time you restart your browser
  2. Install Privacy Badger to see which cookies a site uses, then block them where appropriate
  3. Use an incognito window to open sites and articles that you do not wish to be connected to your regular browsing or purchasing habits

Use incognito mode to stop cookies tracking you

Incognito mode will help protect against browser fingerprinting

Cookies are still the number one method for collecting information online, but browser fingerprinting has become increasingly popular.

With browser fingerprinting, the website you visit will gather information about your browser, the fonts you have installed, and the add-ons or browser extensions you use. This information could be enough to detect you, even if you’re careful about your privacy.

Browser fingerprinting is more of a probability score than an exact match for who’s who on the internet, but it does work and is hard to defend against. Check out EFF’s Panopticlick to see what browser fingerprinting looks like in action.

How to limit the effectiveness of browser fingerprinting

  1. To avoid fingerprinting, run a popular browser that uses no default fonts or extensions, like the Tor Browser
  2. Be careful with extensions, as some extensions are detectable by the sites you visit. The ExpressVPN Chrome Extension is safe to use even in incognito mode.

Incognito mode will stop family members snooping on your computer

If somebody else, like a family member or flatmate, has access to your computer, an incognito window can help you hide certain activity (like buying a birthday present) from them. In fact, it is probably a much better option than deleting your history altogether, which might raise unnecessary suspicion.

Incognito mode won’t stop people tracking you with your DNS records

Every time you visit a website, like ExpressVPN.com, your browser will have to obtain the site’s IP address. The browser will ask a DNS server “what is the IP address of expressvpn.com.” The DNS server then responds with the correct answer, allowing you to connect to the ExpressVPN website.

However, the DNS server may record your queries and sell them to advertisers or pass them on to law enforcement.

By default, your DNS service is supplied by your Internet Service Provider, but it can be changed to one maintained by Google. There are also free DNS services that promise not to pass on your information, such as OpenNIC.

VPN providers like ExpressVPN also maintain their own DNS service, which comes included with a VPN subscription. ExpressVPN does not keep logs and does not pass on any information to advertisers.

Minimize the threat from DNS tracking:

Incognito mode won’t stop system administrators at work or school from tracking you

If you use public Wi-Fi or connect to your school or work network, the administrator can see every site you visit. For sites not encrypted with HTTPS, they are even able to see the contents of the site and all information you exchange with it.

Incognito windows will not protect you from system admins.

Minimize the threat of system admins tracking you

  1. Use Tor or a VPN (or both) to hide your browsing habits from the network administrator.

Be careful if the computer you are using is not yours (such as a computer at school or work). The owner of these devices may have installed other tracking software that will collect information even if you use a VPN or Tor.

Need more options? Use separate browsers or plug-ins!

Browser compartmentalization is an idea that can be an attractive way for power users to get more granularity from browser settings.

For example, a user could configure one browser to accept and remember cookies for regularly visited sites, and another for searching (use duckduckgo!), reading, and other browsing.

This separate browser, unlike an incognito window, can be configured to remember just enough, for example the browsing and search history, but no site cookies or connections to third-party advertising networks.

A screenshot of Chrome's settings page.

Clever ways to configure your browser as a privacy power user. Simply navigate to settings in your favorite browser and use the search bar to customize your tools. Here are some ideas that we use:
Set Duckduckgo as your default search engine

  • Turn off auto-fill
  • Opt out of the “prediction service” that autocompletes your searches
  • Send “Do Not Track” requests
  • Don’t allow sites to check if payment methods are saved
  • Do not use a prediction service to load pages more quickly
  • Set some defaults under “Site Settings”
    • Don’t allow cookies by default
    • Block third-party cookies
    • Ask before sending Location, or allowing camera or microphone access
    • Never allow notifications
    • Don’t allow background sync
    • Don’t allow sites to become default handlers
    • Create exceptions for specific sites, e.g, to allow cookies for a trusted site to function

Is incognito mode really private?

In short, it depends. There are some great reasons to use incognito mode.

  • Hide your browsing history from others using your computer
  • Hide browsing habits from advertisers
  • Avoid browser fingerprinting

Make use of the incognito window when it makes sense! It’s a great tool that will help you maintain control over your own data. Use the Tor Browser and a VPN connection to shield against intruders, and use your own devices whenever possible.

Lexie is the blog's resident tech expert and gets excited about empowerment through technology, space travel, and pancakes with blueberries.