Stealth plugin

It is loaded as a script that runs before the site's own and overwrites values the engine has already decided. The list it goes through is short and widely known, which is part of the problem.

• The automation reading

  The value that says a script is at the controls is set back to false.

• The plugin list and the languages

  Empty arrays are filled with the values a plain browser would carry.

• The graphics strings

  Vendor and renderer are answered from a table rather than from a driver.

• The browser object

  Fields an ordinary build carries are added back so that their absence is not noticed.

A replaced function is a new function, and several ordinary reads say so out loud.

• The source prints

  Asking a function for its own text returns the replacement instead of the native marker.

• The name and the arity differ

  A built-in carries a fixed name and argument count, and a hand written stand-in rarely copies both.

• The shape of the property changes

  A value that was a getter on a prototype becomes an ordinary field on the object.

• A fresh realm is untouched

  A new frame or a worker starts a clean world, and a page reads the original values there.

These four are the values such an add-on usually rewrites, read here in your own browser.

The plugin row is a count rather than a list, because the count alone is already a signal.

The values a profile reports are set inside the engine from a seed handed to it on the launch line. They are in place before any script on the page runs, and they come out of that one seed together, so the parts agree with one another.

So there is no second answer for a page to compare against the first. A fresh frame or a worker opens with the same values as the window above it, and those values read as ordinary native code.

One layer does run in the page here, and the identity is not its job. It holds back the request a tracker fires as you leave a page and the read receipt a chat sends back.

Each build also declares which of these surfaces it answers itself, and a surface it does not answer is covered from the page until a build does. On the engine shipping today nothing of the identity is left to the page.

• An antidetect browser

  A whole browser built to answer as one machine, rather than a page script correcting one after the fact.

• A browser extension

  Something you install for yourself, which a site can often notice by what it changes on the page.

• Headless mode

  A browser with no window, which is a separate tell from anything a patch rewrites.