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.
The user agent string can be accessed with JavaScript on the client side using the navigator.userAgent property.
A typical user agent string looks like this: "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:35.0) Gecko/20100101 Firefox/35.0".
(Source: Mozilla.org)
Contents
The example token indicates Windows 7. Trident/5.0The Trident token identifies the version of MS HTML (Trident) and can be used to determine whether the webpage is displayed in Compatibility View. The Pre-Platform and Post-Platform keys contain values whose names appear before and after the Platform token, respectively.
This ensures that the welcome message is displayed for those using newer versions of the browser. This example properly detects most versions of InternetExplorer, but only if scripting is enabled.
The following example shows an effective way to use conditional comments to display custom content. This example carefully combines downlevel-revealed and downlevel-hidden conditional comments to ensure that each message appears only for the intended browsers.
Feature detection tends to support a broader range of browsers. Internet Explorer 8 on Vista (use this to workaround sites that block Windows 7).
Modify the useragentstring sent by InternetExplorer by editing the Windows registry. Since this tweak involves editing the Windows registry it is strongly recommended that a backup is made before making changes.
Go to File menu export, navigate to a location, give filename and click. Navigate to the following location HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ Internet Settings\5.0\ Sergeant \Post Platform Right-click on the right pane and create a new String Value.
If you want to remove certain values which have been added to the useragentstring by the software you installed navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ Internet Settings\ Sergeant \Post Platform This location might not always exist but if its there you can go there to find some String Values. This policy setting allows you to customize the InternetExplorer version string as reported webbing servers in the HTTP Sergeant header.
I need for a project of mine to change the user agent automatically. You can experiment with it using the latest publicly available Windows 10 build at this moment, which is 9879.
By Sergey Lukashenko on January 2, 2015, last updated on March 22, 2018, in InternetExplorer. 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. User-Agent test and override registry scripts Erica built this page long ago; it's now used as a quick place to poke interesting Web Browser APIs.
Otherwise, run one of the following scripts and restart all browser instances to see the change: The following script commands will generate a text file containing all UA-override registry settings.