Collected research

Detecting Private Browsing Mode

Jeremiah Grossman · blog.jeremiahgrossman.com

Send a visitor to a unique, never-before-seen URL, then use the CSS visited-link colour history hack to test whether that URL now counts as visited. If it does not, a privacy feature is actively blocking history: Safari or Firefox Private Browsing, Chrome Incognito, or IE8 InPrivate. Concept by the author, proof-of-concept code by Collin Jackson.

Record

Researcher

Jeremiah Grossman

Published by

blog.jeremiahgrossman.com

Topic

Other

In the archive

• Collected in the 2009 research round

Related sources

• Private browsing detection

Tags

• css
• side-channel
• info-leak
• detection
• xsleak
• javascript
• browser-fingerprinting
• owasp-a09-2021

This page is the archive's own catalogue record. The research is the work of Jeremiah Grossman, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on 11 August 2026.