A private window starts inside an existing browser profile but uses a temporary browsing session. Guest mode starts a separate temporary profile without the host profile's saved logins and history. The distinction matters on a shared computer.
Private window
Useful when the owner wants a temporary session. Bookmarks and some configured extensions may remain available, while temporary history and cookies are discarded when all private windows close.
Guest mode
Better when another person needs short-term access because it avoids exposing the owner's saved accounts and profile data. Downloads remain on the computer unless removed.
Shared limitations
Neither mode hides activity from websites, network operators or device-management software. Files, bookmarks and information submitted online can persist outside browser history.
Choose by ownership
Use private browsing for your temporary session and guest mode for someone else's session on your device. For a public computer, avoid sensitive accounts entirely when a trusted personal device is available.
Downloads are the common surprise
Both modes can leave downloaded files on disk even when the browser removes the download list. On a shared device, delete the file securely and check the default downloads folder. Printing, screenshots and copied clipboard data also exist outside browser history.
For account recovery
A private or guest session may trigger extra security checks because saved device state is absent. Do not start a critical recovery flow on an unfamiliar public computer when a trusted device is available.
Choose based on the starting state
A private window normally starts from your existing browser installation and may allow selected extensions, bookmarks or saved credentials. Guest mode aims to create a session separate from the usual profile. Exact behavior differs by browser, so check its current help page rather than assuming the labels are identical.
Neither mode makes the network private
Websites, employers, schools and internet providers can still observe relevant traffic, and account sign-in identifies the user. Downloads, printed pages, screenshots and clipboard contents can remain after the window closes.
On a public computer, avoid sensitive work entirely when possible. Closing a guest session reduces local history, but malware, keyloggers and administrator monitoring sit outside the browser's cleanup promise.
The starting state is the practical difference
A private window normally starts inside the existing browser profile. It may still use bookmarks, saved passwords, certificates and extensions, while clearing temporary history and cookies when the private session closes. Guest mode starts with less connection to the regular profile and is often safer when another person briefly uses the device.
Neither mode hides the public IP, defeats workplace monitoring or prevents a website from identifying a logged-in account. Downloads, printed documents, screenshots and clipboard data can remain after the browser window is closed.
Choose based on device ownership
Use a private window to keep a temporary session out of your own ordinary history. Use guest mode when lending your browser and you want to reduce access to your saved profile. Avoid sensitive work on an untrusted public computer because keyloggers, screen capture and local administration operate outside browser privacy modes.
Before closing, sign out of important accounts and check downloaded files. A critical recovery flow may trigger extra verification when profile state is absent, so use a trusted device when one is available.