Getting the User Agent with JavaScript

Question

I'd like to get a script that can grab the user's user agent and prop it to an attribute.

I'm making a website problems contact form and I usually need to know what browser the user is using. How can I detect the user agent string and prop it as the value of an input element.

My html looks something like:

<input type="hidden" id="UserAgent" name="User Agent" />

I want the user agent to be added to that as the value attribute so it would look like:

<input type="hidden" id="UserAgent" name="User Agent" value="Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_3) AppleWebKit/534.53.11 (KHTML, like Gecko) Version/5.1.3 Safari/534.53.10" />

Allgood

You should not need any JavaScript to do this. Just read the user-agent-string from the HTTP header. – Elbe

@Bergi: Actually that's only if you want it at the server-side. With JavaScript - navigator.userAgent should suffice as per accepted answer. – Deluca

@Robin: OP is asking for server side, he wants to get the UA string posted with his contact form. – Elbe

Not if you are generating parts of your application client side. Which seems to be what he was doing. – Motion

Answer 1

Pure Javascript

document.getElementById('UserAgent').value = navigator.userAgent;

<input type="text" id="UserAgent">

jQuery

$('#UserAgent').val(navigator.userAgent);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

<input type="text" id="UserAgent">

Exaggeration

Please add a non-JQuery alternative to the answer. So many new developers think that jQuery is Javascript :-( – Andresandresen

Will not work in jQuery 1.9 or later unless the jQuery Migrate plugin is included. – Potomac

@Potomac this is not true. The example itself is using jQuery 1.11.1 and does not use the Migrate plugin. – Exaggeration

@AdamMerrifield you are right! i said for $.browser and dont could edit the comment. – Potomac

Answer 2

Original Q didn't say anything about jQuery. so

document.getElementById('UserAgent').value = navigator.userAgent;

Endmost