What is private browsing?
What is a browser?
When you use the internet, an application called a browser makes it easy to access and view websites. You are probably familiar with browsers like Chrome (made by Google), Firefox (made by Mozilla), and Safari (made by Apple). A browser is different than a search engine. A search engine is a website and sometimes an app. Search engines like Google Search, Bing, or DuckDuckGo are designed to access and retrieve information. Browsers are designed to allow us to interact with websites. In a future post, we will answer, How do browsers work?
What is private browsing?
Although it is nearly impossible to be completely invisible online, you can reduce your digital footprint through your browsing behavior. You have a choice in what browser you use. Each one offers different out-of-the-box configurations and optional features, to make your browsing more, or less, private.
In addition to various privacy features, some browsers offer different “private” modes, like Incognito in Chrome or Private in Firefox and Safari. These different modes only means the browser and the computer do not save your activity, like your browsing history or cookies.
Private browsing only means the browser forgets some information, and only on your computer. Anytime you are on the internet, there are other groups involved too and we’ll write more about those others later.
What isn’t private browsing?
Regardless of what browser you use, you’re not completely anonymous. (Achieving anonymity over the internet is actually quite difficult if not impossible).
- Websites still see your IP address. While an IP address isn't as specific as your full address, it’s similar to your zip code.
- Any extensions you are using can still track your activity until you close the session.
- Any bookmarks you create or files you download remain after you close your incognito session.
- If you log into a site in private mode, the activity you do on the site will be remembered by the host. For example, when you log into your Facebook account while private browsing, Facebook still records your activity.
- Using Private or Incognito mode protects you from cross site tracking
What are your options?
You can certainly browse in private modes. You can also use extensions. Will Monge describes some of these in What can I do to protect myself from trackers? Another option is to configure your browser to delete cookies, block ads, and prevent fingerprinting. Privacy Guides provides step-by-step instructions on how to make these changes in the various browsers. And if you don’t want to mess around with this, the Brave browser includes many of the features by default. To be as anonymous as possible, you can explore using Tor.
These options do different things and don't necessarily overlap. Using one doesn't mean you are covered by the others. In another Data Curious question, we will go into more detail about what the differences are between these options.
Thanks to Maritza Johnson and Will Monge for their review and thoughtful comments.
 If you use Tor or a VPN, the website sees an IP, just not yours.