How to implement a js processing-support check on the client?

Question

PHP

Maybe someone came across the fact that the user turned off js, or does not support his device at all? I had only 1 option in my head, this is to create 2 versions.
The question is how to implement this check ... in php
For example, if js is processed, then we transfer it to the 1st version of the engine ... If not, then to the 2nd.
There was a question, how then to determine which version is suitable, I decided to write to the session, then I decided to do it easier ... Create 2 folders on the server (1st and 2nd version) and ind. do a check, and then connect this or that folder...
Don’t send it to Google, I haven’t been able to find something like this for a month now, I can’t do a damn thing myself (
I tried to send a simple js, if it was executed, then the 1st version was loaded ... if not, then the 2nd...
Somehow it worked, but it's a terrible crutch...

Answer 1

Try noscript and redirect to another folder. As an option

<noscript>
     <META HTTP-EQUIV="REFRESH" CONTENT="0; URL=http://site.ru/noscript/">
</noscript>

htmlbook.ru/html/noscript
htmlbook.ru/html/meta/http-equiv

Answer 2

I would have scored on this one user in a million, honestly, in 2014.

Answer 3

You can have your own options .. but it's hard to do without js ... Needed for dynamism .. mainly ajax. But making an application that can work with or without ajax is too difficult ... I didn’t succeed (
You can do everything in php, but this is a bad option

Answer 4

Now the question is almost out of topic, how to distinguish between devices like mobile, touch pc and ordinary pc. Except css3 and php userag. not like ?