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".
We've had to do this because otherwise we get constantly overrun by inconsiderate or malfunctioning bots which overload the system. As such, we're forced to block traffic from popular web hosting companies, VPNs and Proxies, we also rate limit requests and have some other checks too.
If you need to get access to the listings of user agents you can either get them in an easy-to-use database download or via the API. Making statements based on opinion; back them up with references or personal experience.
The User-Agent tells the server what the visiting device is (among many other things) and this information can be used to determine what content to return. Of course this requires using a device detection solution which translates UAS into understandable software and hardware information.
If you’d like to learn more on these devices, just copy and paste the UAS to our User-Agent testing tool. As Apple do not pass much info through the User Agent, version numbers don't allow us to differentiate between iPhone models.
User agent allows web server to respond separately to different system or apply different behavior and features to different browser. To access these contents from the desktop or laptop and notebook computer, which has a bigger LCD screen, instead of having to view the web pages on the comparably small screen, user can change the user agent string on the PC web browser.
Click on Develop, and then select User Agent in the pull down menu. Now the both Firefox and Safari browsers is surfing the web by telling everybody that you’re indeed using an iPhone to connect to Internet.
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+.
An often overlooked part of the discussion is that when engaged with a native app some portion of this time is spent actually on the web, via a web view. We’ll get to what a web view is in a minute, but for now, what this means is that although the user is in an app, he or she is effectively browsing the web.
Apart from skewing the numbers, or at least muddying them a little, in the app vs web debate, there are some consequences of this for developers and publishers to consider: A web view is pretty much a browser wrapped inside an app.
What’s happening is that Facebook is making use of the phone’s web view component to open the link. The first shows google.com loaded via Facebook web view, and the second via Chrome browser, both on Android.
This is not too much of a big deal, although it does make changing URL impossible. And if you do log in in on the web view, it’s a different session than the one on your native browser.
And, while we’re talking about cookies, we should probably mention you’ve no control over them in the web view anyway! Now take a look at the second pair of images, this time showing the respective menus of the web view and native browser.
Forcing users to use web views also denies other full-fledged browser benefits. When requesting pages, web views send User-Agent headers, just like regular browsers.
Things get even more interesting when we look at some popular iOS apps: It’s a lot longer than its Android counterpart, but otherwise the structure is more or less the same: platform web view User-Agent, followed by Facebook data.
The first is that the web view, in the Android case anyway, is essentially a different or older browser, and as such the set of features supported is not the same. The second implication is that the web view is indeed detectable, and can be distinguished from the native browser.
Review v30WebView v33WebView v36Chrome NBS WebGL xx WebRTC xx Audio xx Full screen API xxx Form validation x File system API xxx File input type xxx
As we will see a bit later, not only does the HTTP standard suggest things could be done a little better, there are benefits to everyone involved if they are. Let’s take a brief diversion to the HTTP/1.1 standard (RFC7231) to see what it recommends for User-Agent strings.
The “User-Agent” header field contains information about the user agent originating the request, which is often used by servers to help identify the scope of reported interoperability problems, to work around or tailor responses to avoid particular user agent limitations, and for analytics regarding browser or operating system use. Overly long and detailed User-Agent field values increase request latency and the risk of a user being identified against their wishes (“fingerprinting”).
For example, device ids, IMEI, usernames, phone numbers, even preferred language should not be included. The User-Agent string is not the right place for information like this, and could lead to browser-fingerprinting, and unsolicited, invasive user-profiling.
In particular, the inclusion of operator information Vodafone increases fingerprinting susceptibility. This will ensure maximum compatibility, and also that you will appear in web traffic analytics.
And this would end up looking something like the following, for version 2.0 of app called Awesome Kitten : Well, there are a few reasons really: user experience, web analytics, and app web view targeting.
If you make the User-Agent completely unrecognizable and unmappable to anything already known, then the sites your users visit won’t know what to do with it, and they may receive a fallback or default experience. If, as an app author, you haven’t bothered to change the web view User-Agent string from its default, then there is little chance that you’ll appear on anyone’s website analytics radar as being a source of traffic, even if your app sends a lot of traffic their way.
Having your app web view traffic show up in analytics is definitely desirable. But more than this, it enables the web publisher to modify his or her behavior toward your app.
If you don’t bother with a distinguishable web view User-Agent string, then you run the risk of any traffic coming from your app being unidentifiable in a sea of web analytics data. Having an identifiable web view User-Agent string specific to your app opens up opportunities for web publishers and advertisers to deliver tailored content specifically targeting your app.