Private web browsing doesn’t mean no one is watching

Many people misunderstand incognito mode, and web browsers don’t offer clear explanations

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PARTIAL PRIVACY When you set your web browser to incognito, you’re probably not going as deep undercover as you think.

Matthew Henry/burst (CC0)

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Private web browsing isn’t nearly as private as many people think.

Major web browsers, such as Google’s Chrome and Apple’s Safari, offer a private browsing option, sometimes known as “incognito.” The option allows people to surf the internet through a private window that doesn’t log activity into the browser’s history or influence future autofill recommendations. As such, incognito mode can hide one’s activity from others sharing the same device.

But many believe incorrectly that the privacy setting offers broader protections — even after they’ve read a web browser’s explanation of incognito mode.

In a new study, 460 people were asked to read one web browser’s description of private browsing, and then answer questions about their privacy expectations while using the tool. (See some sample questions below in our quiz.) The researchers are scheduled to report their findings April 26 at the Web Conference in Lyon, France.

Respondents expressed significant misconceptions about incognito mode, no matter which browser explanation they read. For instance, more than half of respondents thought logging into a Google account through a private window meant Google couldn’t record their search history. Not true. About a quarter of participants believed private browsing cloaked their device’s IP address, a unique ID number that can be used to approximate physical location. It doesn’t.   

Blase Ur, a computer security and privacy researcher at the University of Chicago, and colleagues suggest companies could mitigate this confusion by providing clearer, more explicit explanations of incognito mode. For instance, these descriptions should avoid vague, sweeping promises of anonymity, such as Opera’s assurance that “your secrets are safe” and Firefox’s encouragement to “browse like no one’s watching.”


Mistaken assumptions

Many people overestimate the privacy offered by web browsers in incognito mode. Find out how much you know about private web browsing, and see how you stack up against the study’s 460 respondents.

H. Thompson; Source: Y. Wu et al/The Web Conference 2018

Previously the staff writer for physical sciences at Science News, Maria Temming is the assistant managing editor at Science News Explores. She has bachelor's degrees in physics and English, and a master's in science writing.