Incognito or private-browsing mode starts a separate browser session and usually removes that session’s ordinary history, cookies and form data from the browser when all private windows close. It does not make the user anonymous, hide the connection from an ISP or employer, prevent websites from recording activity, or erase downloaded files and bookmarks.
Last reviewed: 26 August 2026 · 8 min read
What private mode is designed to do
Private browsing primarily reduces traces left in the browser profile on the device. It is useful when:
- signing into an account temporarily on a trusted shared computer;
- comparing a website without existing login cookies;
- testing how a site behaves for a signed-out visitor;
- keeping a one-off search out of ordinary browser history; or
- using a second session without signing out of the first.
It is not an invisibility service.
What normally disappears after the session
When every private window closes, the browser generally removes session information such as:
- visited-page history stored by that browser profile;
- private-session cookies and site data;
- form and search entries not otherwise saved; and
- permissions or session state created for the private window.
Exact behaviour differs by browser and version. Extensions may be disabled by default or allowed separately.
What can remain
Private mode does not automatically remove:
- downloaded files;
- bookmarks created during the session;
- files opened or edited outside the browser;
- activity saved by a signed-in website account;
- operating-system, security or enterprise-management logs;
- malware or unwanted browser extensions;
- network records; or
- messages, purchases and posts sent to other people.
Closing the window does not reverse an action completed online.
Who may still observe activity?
The website or app
The service sees requests made to it and can associate them with a login, IP address, device signals or other identifiers under its policy.
The network administrator
A school, employer, public hotspot or ISP may observe network metadata according to the connection technologies and its systems. Private mode does not create a tunnel.
The device owner or security software
Managed devices may have monitoring, filtering or endpoint-security tools outside the browser. Incognito does not override them.
Other participants
A person who receives a message, payment or shared file has their own record. Private browsing cannot retract it.
Signing in changes the privacy context
If a user signs into an email, search, shopping or social account, the service can connect activity to that account during the session. Private mode may stop the browser from keeping the login cookie after closure, but it does not tell the service to forget activity already recorded.
Similarly, accepting a website’s tracking consent or entering identifying details can reveal identity within the session.
Incognito does not make an unsafe site safe
Private browsing does not:
- verify a sender;
- detect every phishing site;
- protect a password entered into a lookalike domain;
- remove malware from a device;
- make an HTTP page encrypted; or
- stop a scam payment.
Use How to Check Whether a Website or Payment Link Is Legitimate for the trust decision.
Shared-device precautions
If a trusted shared device must be used:
- Use private mode.
- Confirm the browser and operating system are genuine and updated.
- Avoid saving passwords or payment methods.
- Do not enable synchronisation.
- Sign out of the service before closing.
- Close every private window.
- Remove downloaded sensitive files securely.
- Prefer your own device for banking, primary email or account recovery.
Never use an untrusted public computer for high-value recovery merely because private mode is available.
Private browsing versus clearing history
Clearing history after normal browsing removes selected stored data retrospectively. Private mode creates a separated session intended not to add the same local history to the ordinary profile.
Neither action removes data held by a website, another person, a workplace system or the network provider.
Sources
- Google Chrome: Browse in Incognito Mode
- Mozilla: Private Browsing Without Saving History
- Mozilla: Common Myths About Private Browsing
- FTC: How Websites and Apps Collect and Use Information
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