Check guide · In the browser

Fingerprint surfaces

The long tail: extensions, voices, media, sensors, policies.

What this check is

Beyond the headline probes there is a long tail of small facts a page can read: which well-known extensions answer, which speech voices are installed, what media and DRM modules exist, what the sensors say, what the document policy allows, whether DevTools is open. This check gathers that surface and shows its size.

What Tells reads

Extension probes against a set of known extensions
Speech synthesis voices
Media and DRM capability, sensor availability, document policy, DevTools state

How to read your result

Pass / informational: The surfaces are reported, not scored on their own. Their weight is in combination: each is a small fact, and together they single out one browser in a crowd.
Not available: The surface readings did not arrive.

Why it matters

No serious site bans a browser for having an unusual voice list. Surfaces matter the way details in a story matter: one oddity is nothing, six oddities in the same direction are a pattern, and a pattern that matches a known automation stack's defaults is a recognition. They are also the surfaces anti-fingerprinting tools most often forget to normalize.

Where this matters most

Across the platforms Blowhorn works with, rated in the platform guide (H = matters a lot, M = contributes, L = no public evidence; tags mark vendor-stated, reported, or inferred evidence):

LinkedIn (H): probes for 6,000+ installed extensions; the best-documented cell in this matrix [Reported]
X (M): no public equivalent is documented; standard surface checks assumed [Inference]

Everywhere else in the set this one rates Low.

In your report

Find it in the checks table on the tool page, with the detail in the Surface indicators section. The same findings appear in the report JSON under verdict.reasons, and the agent guide explains how to read them programmatically.