Why a profile has no noise

What noise is

A site can draw text and shapes on an invisible canvas and read the pixels back. The result depends on the graphics chip, the driver, the fonts and the engine - which is how devices are told apart. Noise is random changes to the pixels as they are read. The idea is to get a “different” fingerprint every time.

Why noise shows

It contradicts everything else. The canvas says one thing, WebGL another, the font metrics a third. A real device does not look like that, and fingerprint tests look for exactly these mismatches.

It reaches neither workers nor the server. A script adding noise in the page does not control the code in workers. And a service sees the TLS handshake, HTTP/2 and the order of headers before the page runs a single line.

It is a signal in itself. A test can draw the same thing twice and compare, or check whether built-in functions were replaced. Noise it finds is flagged for what it is - forgery.

What Lumen does instead

A Lumen profile is real Safari on your Mac. It adds nothing: canvas, WebGL, fonts and screen are exactly what Safari would show.

We check this on every build. The same probe of 448 signals runs in Safari and in a profile on one machine. 434 match; the 14 differences are explained, and none of them is about canvas, WebGL or fonts.

Noise tries to pass you off as someone else. A match leaves you as what you are: Safari on a Mac.

So what tells profiles apart

What really is different:

• storage - every profile has its own cookies, localStorage and cache;
• network - every profile has its own proxy, and so its own address;
• language and time zone - from the proxy’s country, at the level of the process.

Hardware signals - the graphics chip, the screen, the system fonts - are the same for every profile on one Mac, as for every tab of one Safari. We do not hide that: they cannot be changed honestly, and changing them dishonestly means going back to noise.

Check it yourself

Open the same fingerprint test page in Safari and in a profile on one Mac. The values match - apart from a few interfaces a profile turns off so that nothing goes around the proxy. They are listed on How we verify.