Show HN: Detect which iOS devices are used on your site | Hacker News Reader

Show HN: Detect which iOS devices are used on your site

dieulot.fr

166 pointsdieulot37 comments

Not device-type, looks famous.co can infer battery mode from Safari: https://imgur.com/a/XvAGvWS

They’re trying to autoplay a video, which Safari blocks if the device is in low power mode. https://pastebin.com/xxN2VPi4 Nice find!

Why include the lookup table in the client code? If you're just mapping (CPU, resolution) to a model, why not just send that tuple to your analytics framework and look it up when displaying? Doing the lookup on the client code means every client has to download the table, and you have to blow away their cached copy whenever you come up with an improvement in the mapping. Limiting it to iDevices certainly makes this table smaller, but I feel like that's a starting off point only... real websites are going to want data about other platforms.

> Why include the lookup table in the client code?

maybe it’s a static site.

The example was sending the data to Google Analytics, though.

static sites can use google analytics. google analytics is a client side include.

I’ve set up a few static landing pages, and used google analytics to see how much traffic they’re getting, if any

Which reinforces the need to do the lookup in client code since you can't code it into GA.

I mean you could just get the data from the client that the lookup needs and then send that data to your server for your server to do the lookup and then return the result to the client

but maybe it’s a static site

It recognized an iPhone X as iPhone 8 plus.

I visited it on an iPhone X and it did “Your device is an iPhone X” for me, but I believe you. Not sure why you’re getting downvotes for reporting your own actual user experience... especially on a Show HN... am I missing something?

It seems that beyond the generation it tries to guess the rest based on the screen res changing the font size and DPI via accessibility settings switches between XS and XS max for me.

Not surprising, as they have the same GPU.

There's also navigator.hardwareConcurrency which can tell you the number of CPU threads available to a device.

Unfortunately, it looks like Apple caps this value to 2 on iOS for anti-fingerprinting purposes.

Sounds more like “fortunately” for iOS users...

Fortunately for privacy; unfortunately for the performance of heavy webapps that may need an accurate hardware.navigatorConcurrency value for CPU scaling.

I hear a tiny violin playing a sad song..

How many heavy web apps that would need it actually run on an iOS device?

I recently wondered how the "Login alert for Mobile Safari on Apple iPhone 7 Plus"-email from Facebook could tell my what device I used to log in to the html version of Facebook. They must be doing the same correlation between SOC and screen size that is mentioned in the article.

I’ve long assumed that websites could tell what kind of device I’m using. Is that not true?

On my Google Analytics account, it shows Android mobile devices as their full model names, but iPhones and iPads as just Apple iPhone/iPad.

I'm sure Google could still narrow it down using other factors, like screen size, but they're not sharing that with Analytics users.

Android Chrome includes phone model in the user-agent.

You can get some details from the User-Agent header https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Us...

You can also get some information from media queries https://developer.mozilla.org/en-US/docs/Web/CSS/Media_Queri...

There's other system information you can get from the browser as well

Sometimes you can use this data to see what device/model is being used (although it's trivial to spoof it). In this case, it seems like apple makes it hard to tell exactly which model is being used, so OP is trying to make it easier.

pretty neat. what would be the best way for me to block this

Probably disabling JavaScript. That worked for me.

Would also recommend you file a bug at https://bugreport.apple.com.

This is linked directly to their internal bug tracker (Radar) so I can assure you it will be read and triaged by an engineering or product manager.

And you might even get a message "Closed as duplicate" three months later...

Nice, could be useful when I’m trying to answer someones questions about their phone remotely and they don’t know which one they have.

But realistically speaking, ad networks are going to add this to their code to gather even more information about you.

To be honest, it would surprise me if they are not already doing this.

On a side note, when you install, launch and maximize TOR browser, you get a warning advising you not to maximize it. Web servers/attackers can use max screen size as an additional point to determine your identity.

That’s confusing. Wouldn’t it be better if everyone maximised their window? If you have a random window size you have a much higher chance of it being unique.

> If you have a random window size you have a much higher chance of it being unique.

That's the whole point, multiple unique data points can whittle down the differences to a single user.

If your screen resolution is common, it's just a bit or two worth of information. But enough of those bits from various sources and you are unique.

The default TOR viewport size isn't random. It picks a multiple of 200x100, with 1000x1000 as the maximum

I think the idea is preventing tracking a user between different Tor Browser sessions, not within the same session. When Tor Browser opens, it opens at a default size, regardless of computer. So there's no way to differentiate between different Tor Browser users who don't manually change the window size.

Maybe? Probably not that useful for most ads. Unless you’re selling phone cases, iPhone 8 and XS users are probably getting the same ads.

Definitely!

I also use https://www.whatismybrowser.com for that kind of thing too.

Man, I needed this last summer when I was doing a huge project. Glad someone can benefit from it!

Reply on news.ycombinator.com