User Agent Lookup

What is User Agent

A user agent is a software application or program that acts on behalf of a user when interacting with a system or network. It provides identification and context about the user or the software making a request to a server.

In the context of web browsing, a user agent refers to the software, typically a web browser, that is used to access and retrieve web content from servers. When a web browser makes a request to a server to retrieve a web page, it includes a user agent string in the request headers. The user agent string contains information about the browser, its version, and the operating system it is running on. This information helps the server to understand the capabilities of the client and deliver content that is compatible with the requesting software.

Websites can use the user agent information to optimize the content or provide different versions of a web page based on the capabilities or preferences of the user's browser. For example, a website might deliver a mobile-optimized version of a page to a user accessing it from a smartphone, or it might provide different CSS styles or scripting code based on the capabilities of the browser.

However, it's worth noting that the user agent string can be modified or manipulated by users or applications, and some web browsers offer options to change the user agent string to mimic a different browser or device. This can be done for various reasons, such as bypassing browser-specific restrictions or accessing content that is otherwise limited to certain browsers or devices.