Which library to use to accurately determine the user's browser and operating system by headers?

Question

Browsers

I am writing an application in node.js. There was a need to determine the user's operating system and browser as accurately as possible.
Recommend some library on node.js for this.
If there is none, then it is possible for any platform (php, c#, ...), I think it will not be difficult to port it to node.js)

Answer 1

https://github.com/tobie/ua-parser
But I hope this is how you collect statistics or something like that, and do not wedge in browsers.

Answer 2

No matter how you search, there is a very big problem with determining the latest versions of IE. I advise you to abandon the definition of browsers altogether.