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".
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).
I'm not sure how contiguous these are across Brave versions, but I noted two in the window.navigator object that are blanked out: plugins and mistypes. Since Brave is meant to be a privacy browser I think it's a good chance these will remain blanked.
If you search DuckDuckGo for they will return Brave. But Chrome itself add a lot (1768 as for now) of chrome-specific properties to window object.
Earn Aeyoun3,80022 gold badges2626 silver badges4646 bronze badges There is a way to check if the user is using brave without any API calls.
I love what Brave has been doing, and I’ve been doing some extensive testing to get a better feel for it. The worst part is that many of us enthusiasts who use fingerprinting protection are possibly running beta versions of operating systems.
Sure, you could say, don’t use Beta versions of desktop operating systems, but even then, it’ll still display your current OS version which can easily narrow you down, defeating the purpose of Fingerprint Protection. My hardened Firefox spoofs my entire OS version and makes it seem like it’s a different build which is great.
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. If the problem seems uncommon, it's worth checking if this bug has been reported to the browser vendor via their bug tracking system (Mozilla ; WebKit ; Blink ; Opera).
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.
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.
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.
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 UserAgentString. 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 UserAgentString EdgeHTMLEdge/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).
However, switching your browser ’s user agent no longer requires that you install third-party software, such as extensions. 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. In this article, let’s go over how you can change your user agent in today’s most popular browsers without an extension.
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 useragentstring.
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.
The UA string contains details about the browser type, rendering engine, and operating system. For decades, websites have used UA strings to fine-tune features based on a visitor's technical specifications.
For starters, UA strings have been used by online advertisers as a way to track and fingerprint website visitors. To address these issues, Google said it plans to phase out the importance of UA strings in Chrome by freezing the standard as a whole.
The long-term plan is to unify all Chrome UA strings into generic values that don't reveal too much information about a user. The deprecation of the UA string mechanism is part of a push at Google to improve privacy on the web, but without killing online advertising, the lifeblood of most free websites today.
While all phones come with pre-installed browsers, both Google Play and Apple App Store offer a number of alternative browsers, some focusing on speed and lightness, others on saving bandwidth and blocking ads, and an ever-increasing amount claiming to increase privacy and reduce a users' mobile digital footprint. Feel free to browse the stats for your local market using our Data Explorer tool.
Optimize UX and conversion rate on mobile Boost web performance Target ads and analyze web traffic Enable App analytics and advertising insights 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. It is possible to change or “fake” what your web browser sends as its user agent.