SynthTrail

Headless browser fingerprinting for autonomous agent sessions

Automated browsers leave marks. SynthTrail reads them in the page and lists exactly which ones it found for each flagged session.

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$9.99 a month. No contract. Cancel any time.

The problem: agents that look like Chrome

Most autonomous agents drive a normal-looking browser, so the user-agent alone proves little. You need behavioural and environmental signs that are hard to hide at the same time.

What is checked

Whether the browser reports it is automated, whether it identifies as headless, whether known automation objects or driver traces exist in the page, whether language settings or window size are missing, whether clicks and typing are scripted, and whether pages open faster than a person could.

Scores with reasons

Signals add up to a score and a session is flagged once it is high enough. The report lists the reasons in plain words. SynthTrail does not use invasive device fingerprinting to identify individuals.

Signals in use

Automation flag and headless markers
Automation tool and driver traces
Scripted clicks, typing and form submits
Speed and activity no person would show

Follow the trail on your own site

Paste one snippet and see the synthetic visitors that use your site. Card details are entered on Stripe, never on this site.

Install the snippet