Hacker News Reader

here's my two use-cases: working around browser bugs, figuring out if it's a mobile device (e.g. to hide drag-and-drop features for file uploads)

prominent example for a browser bug: https://catchjs.com/Blog/SameSiteCookies

I have to reduce size/resolution of my canvas for iPad as mobile safari gets really slow with html canvases around 10k x 10k size. It's tricky because mobile safari has exactly the same UA as normal safari.

doesn't it have ipad/iphone in the UA string?

It did at some point but people were nerfing it so Apple got angry and ditched it

well, that sucks

If you want to show the user a list of active sessions (and let them revoke one), it makes sense to try and parse the UA and show them a more readable device name.

Me neither. But some do, especially if they 100% need features working that are half-supported/different for different browsers.

Though, I don't find many examples of it and checking individual features for determining whether an API is available for example (doesn't apply to everything, yes I know) right, non-hacky way to go.

One usage is analytics.