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".
Now Internet Explorer 11 tells websites that it is Firefox running on Linux. By Sergey Lukashenko on January 2, 2015, last updated on March 22, 2018, in Internet Explorer.
Sergey Lukashenko is a software developer from Russia who started Winner back in 2011. On this blog, Sergey is writing about everything connected to Microsoft, Windows and popular software.
There are ways to develop your website to progressively enhance itself based on the availability of features rather than by targeting specific browsers. Using the user agent to detect the browser looks simple, but doing it well is, in fact, a very hard problem.
Also, experts, or people with another point of view, can give you ideas for working around the bug. Your site needs to use a specific Web feature that some browsers don't yet support, and you want to send those users to an older Website with fewer features but that you know will work.
This is the worst reason to use user agent detection because odds are eventually all the other browsers will catch up. The difficulty of successfully using user agent detection is worth a few disruptions to the purity of your HTML.
Also, rethink your design: can you use progressive enhancement or fluid layouts to help remove the need to do this? In those rare cases where behavior differs between browsers, instead of checking the user agent string, you should instead implement a test to detect how the browser implements the API and determine how to use it from that.
Support could have been added to other browsers at any time, but this code would have continued choosing the inferior path. As the above code demonstrates, there is always a way to test browser support without user agent sniffing.
For example, in the above code snippets, using look behind in short-regexp notation (e.g. /reg/IGM) will cause a parser error in unsupported browsers. Progressive enhancement This design technique involves developing your Website in 'layers', using a bottom-up approach, starting with a simpler layer and improving the capabilities of the site in successive layers, each using more features.
Graceful degradation This is a top-down approach in which you build the best possible site using all the features you want, then tweak it to make it work on older browsers. People use user agent sniffing to detect if the users' device is touch-friendly and has a small screen, so they can optimize their website accordingly.
While user agent sniffing can sometimes detect these, not all devices are the same: some mobile devices have big screened sizes, some desktops have a small touchscreen, some people use smart TV's which are an entirely different ballgame altogether, and some people can dynamically change the width and height of their screen by flipping their tablet on its side! Rather, add in touch conveniences such as bigger, more easily clickable buttons (you can do this using CSS by increasing the font size).
Here is an example of code that increases the padding of #exampleButton to 1em on mobile devices. This effect can be easily achieved using CSS flex boxes, sometimes with floats as a partial fallback. Also try to move less relevant/important information down to the bottom and group the page's content together meaningfully.
Although it is off-topic, perhaps the following detailed example might give you insights and ideas that persuade you to forgo user agent sniffing. The boxes can be separated into multiple columns via two equally fair method.
The second method uses a Column layout and resents all the dogs to the left and all the cats to the right. Only in this particular scenario, it is appropriate to provide no fallback for the flex boxes/multi columns, resulting in a single column of very wide boxes on old browsers.
If more people visit the webpage to see the cats, then it might be a good idea to put all the cats higher in the source code than the dogs so that more people can find what they are looking for faster on smaller screens where the content collapses down to one column. Next, always make your code dynamic. The user can flip their mobile device on its side, changing the width and height of the page.
Or, there might be some weird flip-phone-like device thing in the future where flipping it out extends the screen. The simplest way to do this is to separate all the code that moves content around based on screen size to a single function that is called when the page is loaded and at each resize event thereafter.
Also note that there is a huge difference between the media queries (max-width: 25em), not all and (min-width: 25em), and (max-width: 24.99em) : (max-width: 25em) excludes (max-width: 25em), whereas not all and (min-width: 25em) includes (max-width: 25em). One such case is using user agent sniffing as a fallback when detecting if the device has a touch screen.
Internet Explorer (on Windows) and WebKit (on iOS) are two perfect examples. However, Internet Explorer was such a special little wasp exception prior to version 9 that it was very easy to detect the browser based upon the browser-specific features available.
WebKit is a bit worse because Apple forces all the browsers on IOS to use WebKit internally, thus the user has no way to get a better more updated browser on older devices. For example, WebKit 6 has a bug whereby when the device orientation changes, the browser might not fire MediaQueryList listeners when it should.
Most browsers set the name and version in the format BrowserName/VersionNumber, with the notable exception of Internet Explorer. So to detect Safari you have to check for the Safari string and the absence of the Chrome string, Chromium often reports itself as Chrome too or Sea monkey sometimes reports itself as Firefox.
The browser version is often, but not always, put in the value part of the BrowserName/VersionNumber token in the Sergeant String. There are five major rendering engines: Trident, Gecko, Presto, Blink, and WebKit.
It is therefore important to pay attention not to trigger false-positives when detecting the rendering engine. Must containGeckoGecko/xyzWebKitAppleWebKit/pay attention, WebKit browsers add a 'like Gecko' string that may trigger false positive for Gecko if the detection is not careful. PrestoOpera/XYZ Note: Presto is no longer used in Opera browser builds >= version 15 (see 'Blink')Trident Trident/Internet Explorer put this token in the comment part of the Sergeant StringEdgeHTMLEdge/the non-Chromium Edge puts its engine version after the Edge/ token, not the application version.
Note: Edge HTML is no longer used in Edge browser builds >= version 79 (see 'Blink'). BlinkChrome/XYZ Most rendering engines put the version number in the RenderingEngine/VersionNumber token, with the notable exception of Gecko. The Operating System is given in most Sergeant strings (although not web-focused platforms like Firefox OS), but the format varies a lot.
They indicate the OS, but also often its version and information on the relying on hardware (32 or 64 bits, or Intel/PPC for Mac). Like in all cases, these strings may change in the future, one should use them only in conjunction with the detection of already released browsers.
A technological survey must be in place to adapt the script when new browser versions are coming out. The most common reason to perform user agent sniffing is to determine which type of device the browser runs on.
Never assume that a browser or a rendering engine only runs on one type of device. Never use the OS token to define if a browser is on mobile, tablet or desktop.
Internet Explorer Immobile/XYZ token in the comment. Mozilla/5.0 (compatible; MSI 9.0; Windows Phone OS 7.5; Trident/5.0; Immobile/9.0)Edge on Windows 10 Mobile/XYZ & Edge/ tokens outside the comment. Mozilla/5.0 (Windows Phone 10.0; Android 6.0.1; Xbox; Xbox One) Apple WebKit/537.36 (HTML, like Gecko) Chrome/58.0.3029.110 Mobile Safari/537.36 Edge/16.16299In summary, we recommend looking for the string “Mob” anywhere in the Sergeant to detect a mobile device. If the device is large enough that it's not marked with “Mob”, you should serve your desktop site (which, as a best practice, should support touch input anyway, as more desktop machines are appearing with touchscreens).
Making statements based on opinion; back them up with references or personal experience. I have encountered some sites that claim false incompatibility with Internet Explorer 11.
Some sites, such as YouTube and Yahoo Mail, display an annoying warning that IE is not supported and I should consider another browser, however they do work fine without any noticeable compatibility issue! Other sites, such as Vodafone Greece, are even worse by denying to load at all unless I open them in another browser such as Firefox.
Other sites, such as Vodafone Greece, are even worse by denying to load at all unless I open them in another browser such as Firefox. I want to use Internet Explorer 11 instead, so I tried to open the Developer settings and change the user agent in Firefox or Chrome, but apparently I did not do that correctly, all the affected sites still detect I run IE 11.
User agent changes successfully but cannot trick Vodafone or YouTube. An user agent (UA) string is able to be used to detect what version of a specific browser is being used on a certain operating system.
Mapping UA string tokens to a more human-readable browser name for use in code is a common pattern on the web today. When mapping the new Edge token to a browser name, Microsoft recommends using a different name than the one developer used for the legacy version of Microsoft Edge to avoid accidentally applying any legacy workarounds that are not applicable to Chromium-based browsers.
When Microsoft is notified about these types of issues, website owners are contacted and informed about the updated UA. In these cases, Microsoft uses a list of UA overrides in our Beta and Stable channels to maximize compatibility for users who access these sites.
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. This allows you to request web pages intended for different browsers–or even different devices, like smartphones and tablets.
Click the menu button to the right of the “Console” tab at the bottom of the Developer Tools pane and select “Network Conditions” 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.
You can find extensive lists of user agents on various websites, such as this one. It only applies to the current tab, and only while the F12 Developer Tools pane is open.
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There's no “standard” way of writing an user agent string, so different web browsers use different formats (some are wildly different), and many web browsers cram loads of information into their user agents. Some mobile web browsers will let you change what the browser identifies itself as (i.e. “Mobile Mode” or “Desktop Mode”) in order to access certain websites that only allow desktop computers.
I couldn't find Safari 13 specific IEuseragent string either. If Apple don't provide one, it is going to be tough to get IEuseragent string working.
Do you have clone backup with previous version of Safari installed? There was a IE extension that used to be free on chrome as well and now they want to charge u for it.
I usually use the developer tab but my computer auto updated itself to 13.0.3 and not IE is gone ... There has not been an Internet Explorer version for Mac in 16 years.
There is no sergeant String that would Identify a current Internet Explorer version on a Mac. If you just want to trick the website into thinking you are using Internet Explorer, then any current version of Internet Explorer you would be using would have to be on Windows, so those strings should work.