Does incognito mode keep everyone from knowing?

When you open an incognito window, the list of pages you viewed in it, the cookies sites placed, and what you typed into forms are erased the moment you close the window. So if a family member who shares the computer opens the history, what you looked at won't show up. That's why it's handy when you're secretly picking out a gift or briefly signing in on someone else's computer.

But not everything disappears. Files you download and bookmarks you add in an incognito window stay. Downloaded photos and documents remain in your downloads folder, so if you want to hide them, you have to delete them yourself.

The internet works by your device and websites sending signals back and forth. Incognito mode only reduces the record left on your side; it doesn't hide those signals themselves. So the sites you visit can tell you came by, and on a work or school Wi-Fi network its administrator can see which sites you connected to, as can your internet provider at home.

If you sign in, even in an incognito window, that site knows right away who you are. If you sign in to a portal in an incognito window and search, those searches can be saved as activity on your account. Even if closing the window erases the cookies, records already stored on the server aren't erased with them.

A 2018 study that surveyed 460 people in the US found that many believed incognito mode hides much more than it really does. They thought, for example, that their employer or internet provider couldn't see their browsing, or that it would block ad tracking. Reading the notice on the browser's opening screen didn't clear up all of these misunderstandings either.

So it's accurate to think of incognito mode as a tool for not leaving a record for people who use the same device. After using a public computer, making a habit of signing out first, incognito window or not, is the surer way to go.