A user agent is a computer program representing a person, for example, a browser in a Web context.
Besides a browser, a user agent could be a bot scraping webpages, a download manager, or another app accessing the Web. Along with each request they make to the server, browsers include a self-identifying User-Agent HTTP header called a user agent (UA) string. This string often identifies the browser, its version number, and its host operating system.
Spam bots, download managers, and some browsers often send a fake UA string to announce themselves as a different client. This is known as user agent spoofing.
A typical user agent string looks like this: "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:35.0) Gecko/20100101 Firefox/35.0".
Choose the string that you need from a preset list (or from custom entries) with the Sergeant Switcher extension. Once you add the extension to Firefox you can access the alternate useragentstring in two ways.
Note: The useragentstring will automatically reset back to the default each time you restart Firefox. You can create, edit, and delete current user agent strings or use the import/export functions.
The Sergeant Switcher extension provides a quick and easy way to change the useragentstring for those less than cooperative websites. For those wanting to add additional user agent strings visit this website (available in XML file format).
This information is extremely useful to the server, as it allows serving or send back content in the most suitable format for the machine and browser you are using. Usually there is no need for this value to be tweaked as most “well-designed” websites will cater all the web browsers correctly.
Some bank websites even test for exact versions of supported browsers. It is not however a good substitute for testing with an actual instance and version of the browser.
For Mozilla Firefox, there are several add-ons available that will easily allow you to change useragentstring on the fly. Control : A highly rated plugin which is pretty simple to use.
It provides the ability to specify user agent strings on a per-domain basis. Sergeant Override : This add-on allows you to change the useragentstring from a toolbar button.
Most of the add-ons provide very similar functionality, so go with one with good rating and works best with your version of Firefox. Firefox provides a config option to change useragentstring.
If you like to use custom user agents for only certain web domains then you might be better off using one of the add-ons mentioned above or refer to the section immediately below this. It is not easy to get to change the configuration, as there is no good user interface to do this.
If for some reason you cannot or don’t want to use the about:config editor, then you can specify these values in either the pref.js or user _pref.js files. You should be able to find these files inside your Firefox profile folder.
Close the Firefox browser Using a file browser or command line, find the file named pref.js (or user _pref.js) inside the Firefox profile folder. If you just changed it for just one or two specific web domains, then there is really no good to test for it.
By changing user agent, sometimes, one can get access to restricted part of a website with extra contents that normally open only to bots, or search engine crawlers. This kind of area typical example is “Member Only” forums or sites that don’t want to lose out on search engine traffic. Modification of useragentstring also enable surfers to trick websites into believing that they are actually using a particular web browser or using specific system in order to avoid and disable advertising display or junk ads that targeted to specific segment of viewers of the websites only.
Once installed and restarted Firefox, simply go to Tools Sergeant Switcher, and you will see a list of user agents which you can choose. By default, there is only a few user agents listed (depending on the versions), which can be Internet Explorer 6 / 7 / 8, Netscape, Opera, various search robots such as Google bot, Minot, Yahoo Slurp and iPhone 3.0.
The second method that you can modify the user agent in Firefox is by performing the following steps, which do not require any download: To change back to the default user agent, simply right-click on the line and select Reset.
OK is a technology writer for Tech Journey with background of system and network administrator. He has be documenting his experiences in digital and technology world for over 15 years. Connect with OK through Tech Journey on Facebook, Twitter or Google+.
User agent is an HTTP request header string identifying browser, application, operating system which connects to the server. Not only browsers have user agent but also bots, search engines crawlers such as Google bot, Google AdSense etc.
Mozilla/5.0 (platform ; RV: gecko version) Gecko/ gecko trail Firefox / firefoxversion Firefox OS phones say Mobile “; the web is the platform.
Appname / app version indicates the application name and version. Firefoxversion will generally represent the equivalent Firefox release corresponding to the given Gecko version.
When Firefox runs on a device that has the phone form factor, there is a Mobile; token in the platform part of the UA string. The preferred way to target content to a device form factor is to use CSS Media Queries.
For increased interoperability, if the browser is running on a version below 4 it will report 4.4. Starting in Version 6, users can opt into using a GeckoView-based Focus for Android with a hidden preference: it uses a GeckoView UA string to advertise Gecko compatibility.
Klein Version (Rendering Engine) UserAgentstring 1.0 (Review)Mozilla/5.0 (Linux; Android 7.0) Apple WebKit/537.36 (HTML, like Gecko) Version/4.0 Klein/1.0 Chrome/58.0.3029.83 Mobile Safari/537.364.1+ (Review)Mozilla/5.0 (Linux; Android 7.0) Apple WebKit/537.36 (HTML, like Gecko) Version/4.0 Focus/4.1 Chrome/62.0.3029.83 Mobile Safari/537.366.0+ (GeckoView)Mozilla/5.0 (Android 7.0; Mobile; RV:62.0) Gecko/62.0 Firefox /62.0 Version 7 of Focus for iOS uses an useragentstring with the following format: Note: this user agent was retrieved from an iPhone XR simulator and may be different on device.
Some of them we have noticed are of the form Nelson; “, Reopen; “, or Open C; (note that putting space is also discouraged). Firefox OS version numberGecko version number1.0.118.01.118.11.226.01.328.01.430.02.032.02.134.02.2372.544It's easy to find the correspondences by looking at the Mercurial repository names : repositories starting by mozilla-b2g are the release repositories for Firefox OS, and have both Firefox OS and Gecko versions in their names.
The first two digits are owned by the Mozilla product team and denote versions with new features (e.g.: v1.1, 1.2, etc). The third digit is incremented with regular version tags (about every 6 weeks) for security updates, and the fourth is owned by the OEM.
Identifier preferences, (see the obsolete Sergeant Strings Reference). In the past, specific plug-ins, add-ons or extensions added user agent parts to notify sites they were installed.
The recommended way to do this, if it's absolutely necessary (remember that it slows down every request) is to set a custom HTTP header. If you ever wanted to make your web traffic seem like it was coming from a different browser–say, to trick a site that claims it’s incompatible with yours–you can.
If you don’t see the console at the bottom, click the menu button in the top right corner of the Developer Tools pane–that’s the button just to the left of the “x”–and select “Show Console”. On the Network conditions tab, uncheck “Select automatically” next to User agent.
It only works while you have the Developer Tools pane open, and it only applies to the current tab. To create the preference, right-click on the about:config page, point to New, and select String.
This setting applies to every open tab and persists until you change it, even if you close and reopen Firefox. To revert Firefox to the default user agent, right-click the “general.user agent.override” preference and select Reset.
Microsoft Edge and Internet Explorer have user agent switchers in their developer tools, and they’re nearly identical. To open them, click the settings menu and select “F12 Developer Tools” or just press F12 on your keyboard.
The developer tools will open in a separate pane at the bottom of the window. Click the “Emulation” tab and choose an user agent from the Useragentstring box.
It only applies to the current tab, and only while the F12 Developer Tools pane is open. Chris has written for The New York Times, been interviewed as a technology expert on TV stations like Miami's NBC 6, and had his work covered by news outlets like the BBC.
Since 2011, Chris has written over 2,000 articles that have been read more than 500 million times---and that's just here at How-To Geek. Learn More I'm running Debian GNU/Linux, where Firefox is called Ice weasel due to licensing restrictions regarding redistribution.
I'm running Debian GNU/Linux, where Firefox is called Ice weasel due to licensing restrictions regarding redistribution. Chosen solution Try to install add-on named Sergeant Switcher.