[ehsankia]

I don't get it. Don't the majority of people browse at full screen, on common devices which all have the same fullscreen dimensions?

Who out there browses to a size, resizes there window, then browses to another website, then resizes again and so on? That makes no sense.

[beatgammit]

Even if they do, there's variation in what "full screen" means. Some people have the bookmarks toolbar enabled, others don't. Some have compact icons, others don't. Some keep a sidebar open, others don't. Some use a theme that changes the size of toolbars. Some have a dock/taskbar always visible, some have differently sized taskbars, etc.

This all leads to a huge variation between users of even the same screen size (e.g. 1920x1080), since the portion of the screen available to the page is different.

The Tor browser fixes this by having the window always be the same size on all machines, regardless of screen resolution. This is a bit annoying because it means you have less stuff on the page visible at a time, but since it makes you look the same as every other user, it's worth it for privacy conscious users.

[nightski]

As a user with an ultrawide monitor I have several browser windows open and arranged in various configurations at all times and often resize them.

Probably not a super common scenario, but not ultra rare either.

[manigandham]

Yes. I'm in adtech. 60% of browsers are mobile/tablet which are already fixed. The rest are almost always fullscreen. Maybe 2% have non-standard sizes.

[meruru]

When you two say fullscreen, surely you mean maximized? I imagine a sizeable fraction of users don't even know how to fullscreen a window.

[manigandham]

yes

[missblit]

Fixed except when the user enables android split-screen mode! I believe split-screen mode implies the height of the browser window can change at runtime (in a JS visible way), but haven't looked at it recently.

[lucasmullens]

I'm not sure what percent of people customize their dock height on macOS, but that setting uses a slider, which would cause a bunch of unique heights for a maximized browser.

[meruru]

The OS chrome between users varies a ton. Each taskbar, dock and titlebar can have their own size. In my case I'm using a window manager without decorations, so I don't even have a titlebar!

[Swenrekcah]

I would actually really like an answer to this question, I’ve often thought about it!

[mrmekon]

Huh, I thought the original was a sarcastic question. In that case, let me explain:

I keep a browser window open at all times. It is never full screen, because if it were full screen I wouldn't be able to see multiple windows at the same time.

I keep my browsing window as close to 1024x768 as possible. In 2019, a lot of websites can't handle a browser window using a mere 75% of the laptop screen, so they either render incorrectly or, worse, switch to a mobile view. When that happens, I either blacklist the website forever in a contemptuous fervor, or just resize the window. Apparently, this resizing action is trackable.

When I say "as close to 1024x768" as possible, I mean exactly 1024x768 unless I have resized it and forgotten. I use a little AppleScript thing to resize it to 1024x768, precisely for browser fingerprinting reasons. When you resize the window by hand, you typically end up with a VERY unique window dimension.

[meruru]

The privacy.resistFingerprinting option will always launch your browser at exactly 1000x1000 size. It's probably preferable to your script.

[Swenrekcah]

Thanks for the answer. I just thought people usually kept their windows at full screen, but reading all the replies perhaps I am the outlier here!

[gnopgnip]

Even if you had 100 users with 1024x768 resolution for their screen they can be fingerprinted further because of small differences in the browser. Zoom setting, toolbar size, bookmarks button showing, full screen mode, small icons, additional toolbars, task bar auto hide, larger than standard taskbar all affect the viewable area of the browser and this is what the site operator or analytics will see.

[ionised]

Browsing in full screen is just a waste of space on my preferred devices.

[joshred]

Does that matter? Don't devs cater to the outliers?

[Swenrekcah]

It matters because if 99% of people have the same 5 configurations and only the outliers are identifiable, then this method would not be as valuable for spying as it is reported to be.

[EGreg]

This! So what’s the answer??