Glossary

Headless browser

A real browser engine run without a visible window, usually under automation. Cheap to run at volume, and increasingly easy for a site to spot.

A headless browser is a browser engine running with no visible interface, driven by a script over an automation protocol. It is the standard tool for testing and for collection at volume, because a machine can run many of them and none of them needs a screen. The engine is real, so scripts execute and the DOM is built — the difference is that nothing is drawn for a person to look at.

The operational problem is that headless mode has always been distinguishable, and the differences are exactly the ones a fingerprint measures: what the graphics stack produces, which fonts resolve, how the window reports its own size, and what the automation protocol leaves visible. Sites that care check. Argus takes the other route — sessions are ordinary Chromium sessions with a window, so the page you collect is the page a person would have seen, with the identity generated in the renderer rather than concealed by a wrapper. That is the argument on the scraping page, and the automations that drive those sessions are documented on the automation page.