The HTTP User-Agent request header is a characteristic string that lets servers and network peers identify the application, operating system, vendor, and/or version of the requesting user agent.
Find out your user agent string, browser, opera system, device and more with this tool. Learn what a user agent is and how it is used for feature detection and compatibility.
Learn what your user agent is and what it reveals about your web browser, operating system, and mobile device. Find out how to change or fake your user agent and why some sites may detect it.
Understand user agents, their role in bot detection, and how to customize them ethically for scraping and automation. Get tips and tools for testing in 2025.
On the Web, a user agent is a software agent responsible for retrieving and facilitating end-user interaction with Web content. [1] This includes all web browsers, such as Google Chrome and Safari, some email clients, standalone download managers like youtube-dl, and other command-line utilities like cURL.
The HTTP header User-Agent is a request header that sends a characteristic string to web servers, allowing them to identify the Operating System (OS) and browser of the client making the request. Every time your browser connects to a website, it includes the User-Agent field in the HTTP header.
Discover what a user agent is and how it facilitates web interactions. Learn about User-Agent strings and their role in web optimization.
Beginner's Guide to User-Agent HTTP Headers in Testing Learn what a User-Agent Header is, how it works, and how to test it effectively. Use Requestly to modify and test different User-Agent strings easily.
Your user agent is a string that web servers use to identify your browser and optimize content delivery. Learn what a user agent is, how to troubleshoot browser issues, and see your user agent details on this site.
What is a user agent? A user agent, or UA, is a string of information that identifies a user's browser and operating system. When you visit a website, your Internet browser sends information to the web page about your web browser, operating system, device, screen resolution, and more.