32

Is there any way to do this? I'm trying to send a GET request to a website, but I want to customize my UserAgent. Is there any way to do this in pure HTML and JavaScript? I'd like it to all execute locally.

user3528112
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  • Possible duplicate of [Mocking a useragent in javascript?](http://stackoverflow.com/questions/1307013/mocking-a-useragent-in-javascript) – APAD1 Apr 23 '14 at 15:18

5 Answers5

18

This is working for me.

Object.defineProperty(navigator, 'userAgent', {
    get: function () { return 'Mozilla/5.0 (Windows NT 6.2; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0)'; }
});

It is an updated version of code4coffee's answer as Object.prototype.__defineGetter__() is deprecated: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/__defineGetter__

c24w
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Peter Rhodes
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10

You can programmatically do this in Javascript (this example mocks up Firefox):

navigator.__defineGetter__('userAgent', function () {
    return "Mozilla/5.0 (Windows NT 6.2; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0)"
});
navigator.__defineGetter__('appName', function () {
    return "Netscape"
});

You can then view the changes in the console via (and of course check these via Javascript):

navigator.userAgent
navigator.appName

Here's an example of a test that should work (using Jasmine):

describe("isUserAgentInternetExplorer", function () {
    it("should return false for Firefox", function () {
        navigator.__defineGetter__('userAgent', function () {
            return "Mozilla/5.0 (Windows NT 6.2; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0)"
        });
        navigator.__defineGetter__('appName', function () {
            return "Netscape"
        });
        //your code here...
        expect(...your code here...).toEqual(false);
    });
});
code4coffee
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4

2022

You are not allowed to modify the following headers, according to Fetch WHATWG spec.
And in 2022 all the evergreen browsers have implemented this requirement.

`Accept-Charset`
`Accept-Encoding`
`Access-Control-Request-Headers`
`Access-Control-Request-Method`
`Connection`
`Content-Length`
`Cookie`
`Cookie2`
`Date`
`DNT`
`Expect`
`Host`
`Keep-Alive`
`Origin`
`Referer`
`TE`
`Trailer`
`Transfer-Encoding`
`Upgrade`
`Via`

As well as headers, starting with proxy- or sec-.

These are forbidden so the user agent remains in full control over them.

avalanche1
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-2

If you are using a XMLHttpRequest you can set a custom Request Header like:

var xhr = new XMLHttpRequest(...);
xhr.setRequestHeader("User-Agent","test");
SeDav
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-5

You will never change a user Agent in HTML, html is the message not messenger.

Indeed you can do it with a javascript code, but it's dangerous if you ever deploy it in production.

It's far safer to use an agent switcher:

https://addons.mozilla.org/fr/firefox/addon/user-agent-switcher/

https://chrome.google.com/webstore/detail/user-agent-switcher-for-c/djflhoibgkdhkhhcedjiklpkjnoahfmg

wako
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