This is a real version of the critique and I've been thinking about it. The page leans on an IP-to-geo lookup that's known to be approximate (city-level on a good day, region-level often, wrong-city sometimes); accuracy isn't the point, any location, given without asking, is the point. But you're right that leading with a wrong answer gives readers permission to dismiss the whole. Considering opening with timezone instead and demoting geo to later, where it lands as "we tried, here's how close we got." Open to better suggestions.

Fair point, and you're right. On iOS the stock font set is essentially uniform across devices in the same OS version, so the "nearly unique" claim doesn't hold there. Just pushed a hedge: prose now distinguishes between desktop (where fonts accumulate via apps and OS over time, and the bundle is genuinely identifying) and iOS/Android (where it isn't, on its own). Combined with screen + GPU + language + timezone the iOS version still narrows the field, but the prose shouldn't overclaim. Thanks.

Thanks for that. The page isn't trying to tell anyone something they don't already know, it's trying to put it in front of the people who haven't been told. The bug reports today have been gold and the volume is meaningfully better for them.

Confirmed. Firefox's privacy hardening returns "Mozilla, or similar" or just "Mozilla" as the renderer string. Chrome doesn't (yet). My parser was treating the Firefox string as if it were ANGLE format and grabbing the wrong half. Fixed.

Right, IP-to-geo is approximate and gets a lot of cases wrong (yours among them). Most ad networks use it as a region/DMA hint, and not precise positioning. The point of including it isn't precision. It's that any location is more than nothing, and the visitor never opted in.

Pedantic but right. The JS queries them; the browser returns them without prompting the user. "Volunteered" is the editorial verb for that round-trip but it does paper over a layer.

It's relevant because connection-level fingerprinting is directly visible to intermediaries like cloudflare.

The 100% charging readout is the desktop-with-no-battery phantom. I pushed a stricter filter for that earlier, you may be on a cached copy (try a hard refresh). On the light-mode call: the page detects your preference but doesn't honor it, intentionally. The irony being that the demo ignores the same signal it points out. I take the cost of the annoyance.

Okay but it's really hard to read for those of us with old people eyes.

I'm 36 and I struggled to read it.

... Wait, 36 isn't old is it??

The Referer header is the one that's hardest to opt out of cleanly, strip it at the network level and too many things break. Referrer-Policy lets the origin set the rule, but the visitor doesn't get to choose. There's a quiet move toward Referrer-Policy: strict-origin-when-cross-origin as a sane default in modern browsers but it's still origin-dictated, not visitor-dictated.

I strip/forge it with a old, probably outdated firefox extension (Referer Control.) But you still got news.ycombinator.com. How? I thought the extension was broken, but it's not.

That was actually my only surprise, everything else I was expecting.

edit: ignore this, looks like I just needed to save my preferences again. Thanks for showing me that I have been leaking my referer for some mysterious amount of time.

Correct on rigor. Proving a fingerprint requires the two-visit protocol you describe. The page doesn't actually compute a stable fingerprint or attempt to track returning visitors, it shows you the signals that go into one. The barcode at the bottom is deterministic from the data shown but isn't compared against anything stored. Sloppier than a real fingerprinting tool, by design.

Right that most of these aren't surprises individually, and right that nobody wants a permission prompt for Accept-Language. The argument isn't that you should, it's that the combination is enough to identify you across sites without your awareness, and that the wider tracking ecosystem trades on that bundle. The piece is editorial about the thing existing, not a proposal to gate every header. Reasonable to push back if you find the bundle isn't the point.

Fingerprinting has exited for a long time. But this site is specifically saying "None of them told you".

The site does seem to be implying that disclosure and consent are the issues:

> We did not ask for your location.

> Nothing about this was requested. The information arrived on its own.

> Your device volunteered all of this in the first milliseconds of the connection. It will do this again on the next page you visit, and the one after that.

> No permission is required.

It's framing this as if browsers are maliciously volunteering information that ought to be protected, and that sites are maliciously hiding the information available to them.

It does seem to be clearly suggesting that even basic pieces of information ought to be available only upon request and that this must be disclosed to users.

You say this is "not a proposal to gate every header", but it's sure looking like something close to that to me.