What private browsing hides, and what it does not

What changes in a private window

Chrome’s Incognito mode starts a separate browsing session. Its session cookies and site data are discarded when that Incognito session ends, and the session is not added to normal browsing history. Files you download and bookmarks you create can remain. Google explains these boundaries in its Incognito documentation.

That makes a private window useful for a small, specific task, such as opening a website without the cookies from your normal session. Before you start, decide what you actually need to separate. A fresh session is a different goal from keeping an activity confidential from the website itself.

What it does not hide

Mozilla explicitly warns that Firefox Private Browsing does not make a person anonymous online. Websites and network operators can still obtain information about activity, and the mode does not protect against spyware on the device. See Mozilla’s explanation of Private Browsing.

Logging in is an especially clear boundary. When you enter an account’s credentials, you are identifying that account to the service. The color of the browser window does not undo that decision. Use an ordinary comparison when judging a privacy claim: who is being prevented from seeing which particular piece of information?

Finish the session deliberately

In Chrome, close every Incognito window to end the session. Closing a single tab is not enough when other Incognito windows remain open. Downloads and saved bookmarks need separate attention because they are not automatically removed with the session. Google documents the closing behavior.

A practical finishing routine is to sign out of accounts, close the private windows, and check whether you saved anything locally. On a shared device, avoid leaving files in an obvious Downloads folder. Only delete files you own and no longer need.

Choose a habit that fits the task

Write your goal in plain language before choosing a setting. “I do not want this session in this browser’s normal history” is reasonably specific. “I want complete privacy” is not, because it leaves out the observer, device, accounts and information involved.

For a shared family computer, consider separate operating-system accounts as part of your own setup plan. For a managed work device, follow the organization’s policies rather than assuming a private window overrides them. For a sensitive situation involving personal safety, seek advice that considers your circumstances instead of relying on a single browser switch.

Private browsing can be a useful boundary. Treat it as one boundary, not an all-purpose privacy promise.

Sources and further reading

1. Google Chrome Help: Browse in Incognito mode Consulted 27 September 2026.
2. Mozilla Support: Private Browsing Consulted 27 September 2026.

Consult the linked documentation for current details. Settings, availability and interface labels may change.