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".
An user agent is a string (line of text) that your browser sends to websites when you access them. User agents are important because sites can use them to modify the content they send to your browser.
For example, if you visit most modern sites in Internet Explorer 6, you’ll see a message that you need to upgrade your browser for proper compatibility. User agents also come into play when browsing on a mobile device, so websites know to show you the mobile-friendly version of a page.
Open Chrome’s Developer Tools by right-clicking anywhere and choosing To inspect, hitting Ctrl + Shift + I, or by pressing F12. On the Network conditions tab, uncheck Select automatically and you can then choose a new user agent from the list.
This lets you easily switch your user agent, including setting certain sites to use a different agent all the time. Press F12 or right-click on an empty spot of the page and choose To inspect element to open the developer tools window.
You’ll need to enable the hidden Develop menu in Safari before you can change your user agent. While there’s no quick toggle to change your user agent in the mobile versions of Chrome and Safari, you can easily make websites think your phone is a computer.
Check the Desktop site box and it will reload to show you the full version. On Safari for iOS, tap the AA button to the left of the address bar and choose Request Desktop Website.
You’ll find the same option in Chrome for iPhone by tapping the Share button at the top-right, followed by scrolling down and choosing Request Desktop Site. While swapping your agent can’t accommodate every possible real-world situation, it lets you get some basic testing done in a fraction of the time.
Further, if backward compatibility is important for your site, swapping your user agent to IE 8 is a lot easier than installing a copy of ancient browsers manually. Browsing mobile versions of pages means you only get the basics and aren’t wasting data on multimedia or other large items.
While not as common as it once was, sometimes you’ll come across websites that tell you Firefox doesn’t work with the page, or you must use Internet Explorer, or other similar warnings. Some people explain that they use these services to get around sites that block entire operating systems.
While there’s really no good reason for a site to block an entire OS, you could run into a page that complains about you using Linux. If you’ve used Windows all your life, you can jump around some sites and see if they look any different when using Mac or Linux.
Some browser -switching agents even allow you to pose as Google bot, the robot Google uses to crawl and index the web. 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.
You can find extensive lists of user agents on various websites, such as this one. 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.
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.
I haven’t found any indications of publishers actively blocking any of these browsers even on a small scale. I’ve found over 21 easily detectable characteristics which are unique to Brave, and it only took me half an hour to discover and test these.
I don’t believe there are any legitimate reason to fingerprint individual users. This, combined with behavior specific to Brave ’s ad-blocking implementation, makes it easy to fingerprint the Brave browser itself.
The previous mechanism detected a special property of the window object. Brave doesn’t care much to maintain compatibility with the Web Platform and standards.
One of the weirder things it does is to remove specific URL query parameters from all requests. To detect Brave : From the client, send a request to a specially crafted URL (below).
Over the past few years, mainstream browsers have all started including such functionality as a part of their developer console or within standard menus. Although uncommon, there is a chance for browser extensions to become hijacked for malicious purposes, which could be a risk to your security.
If you look or scroll down towards the bottom of this panel, you should see a User agent label, which includes a respective set of options. Here, you can select from a set of defined user agents or even enter your own custom user agent string.
If it’s your first time doing so, you should see a disclaimer stating that you’re entering risky territory that’s for advanced users only. If the preference isn’t there, right-click on a blank area of the page, hover New, and select the String option.
Craig is a long-time writer, coder, and marketer with years of experience in the technology and gaming spaces. Since 2008, he's worked remotely with some of the most notable publications in these industries, specializing in Windows, PC hardware and software, automation, and the like.
However, the user agent can also be changed right from inside the browser to “trick” the web server into providing information in a specific way. This is very useful for developers to test their sites, to see how their website looks on different browsers and devices.
Here, click on “Network” located in the left panel and you will see the option of “Spoof Sergeant with a drop down menu below it. The effects will be applied and you can close the developer tools to view properly.
When you will again refresh the page, the effects will be removed and you will see your normal view. Firefox doesn’t really make it that easy to switch user agents.
Download Override and you will see its icon on the right side of the address bar along with a drop down menu button (downward arrow) next to it. Just click on the user agent which you would like to use and make sure the Override icon is “blue” (enabled) not “gray” (disabled).
When you are done, just click on the Override icon and it will turn “gray”, indicating that the add-on is now disabled. In “Preferences”, move to the “Advanced” tab and check the checkbox next to the option “Show develop menu in menu bar” and close the “Preferences” window.
From the side menu, hover your mouse cursor over Sergeant and you will see all the available user agents. Just select any user agent you like and it will be automatically applied (no need to refresh page).
It allows sites to determine specific details, which in turn alters how the page is served to the user. For instance, menus will be easier to touch and read, and text will be more stripped down and readable.
Browsers have a fingerprint that can help uniquely identify users with the user agent being one of these factors. When using Edge, open a page and press the F12 key to access the developer settings.
Select the “Emulation” tab and look for the Sergeant string list.” Here you can choose to make Edge mimic the browser of your choice. Just as with Edge, Chrome has an useragentchange within the developer settings, although it is a lot more complicated to access.
From there click “Tools” and then “Developer Options.” You can also easily access this via the key combination of Ctrl + Shift + I. As you can see below, there will be an option to change the user agent by unpicking the “Select automatically” box.
Open a browser window and type about:config within the address bar. A warning will appear, but it is quite safe to proceed, providing you don’t change settings or flags without due care and attention.
If you don’t fancy the idea of messing with a browser ’s settings, then there are some add-ons and extensions that will do the job for you. It is currently, at the time of writing this article, a featured extension from Firefox, so that may put to rest some concerns that users may have.
Matthew Muller Matt has worked in the tech industry for many years and is now a freelance writer. While all the above sounds great, over time the Sergeant has been misused by some web developers and occasionally even abused by the bigger tech companies, in positions of power.
Vivaldi is frequently blocked, shown alternate (incorrect) versions of a website or spurious warnings are displayed, based solely on the Sergeant. Sometimes it could arguably be considered a mistake, with the development team of a website naively assuming that only browsers they have personally tested be given access to their site, blocking anything that isn’t.
And thus, modern web browsers Agents typically include both their own information and additionally that of other browsers. Although it is a big hack job, it works surprisingly well in much the same way as providing someone else’s name can get you into an exclusive club.
We also often encounter websites that block the exact string “Vivaldi”, with no contact or warning to us. When this happens and error messages are displayed, or intentionally invalid copies of the website are sent our way, users typically assume Vivaldi has an issue, and even sometimes struggle to comprehend that anyone would target us.
In all such cases, we have tried via various means to get someone in the respective companies to stop breaking these sites for our users. Follow-up requests have been made both by us and our more technical fans multiple times since than, via various contact channels but to no avail.
The problem with our current approach is that with the web being almost infinite, we can’t possibly discover all the websites who have blocks set against us. For a handful of sites where we know the label Vivaldi (and our version number) is responsibly used, we will present our full Sergeant.
There is a downside for us in doing this since Vivaldi will effectively disappear from third party rankings of browser popularity (we will be indistinguishable from Chrome) but that is a price we will happily pay to provide the best website compatibility for our users. A fan of Linux (Slackware), uni cycling, simple solutions and a “slow” lifestyle.
Marked as answer by Qinghai HU Friday, January 23, 2009 10:46 AM I want to change it to reporting a Desktop or default user agent.
Since it is a Fire tablet you don’t have access to the Google Play Store. From the silk browser it will ask you if you want to install and give you a warning.