Bots vs Browsers - Public Bot / User Agent Database & Commentary

Bots vs Browsers - database of 16,269,933 user agents and growing

About User Agents

What is a user agent?

A user agent is a text sequence that a browser reports to a web site containing information such as the brand, version, plugins, and toolbars installed on the browser. This information helps web sites determine what capabilities a browser has, and helps the web site provide pages that cater to the browser.

In addition, robots, spiders, or "bots" that surf the web report a user agent to web sites. Bots are automated software that surf web sites looking for information. Popular bots include the Googlebot, MSNBot, and Yahoo! Slurp. These bots crawl the web to find content to include in their search engines.

By checking the user agent of your browser's http request, this site can see the user agent your browser is reporting. The browser you are surfing with is reporting this user agent text:

Your Current User Agent Is:

CCBot/2.0 (

How do User Agents work?

Each web site that reads user agent information must do this by checking the text sent in an HTTP request for a web page. This text is retrieved differently depending on the type of web site that is being surfed. For example, ASP web sites check for user agent text by checking the Request.ServerVariables collection for the "HTTP_USER_AGENT" element.

Checking a User Agent in ASP/ASP.NET

The syntax to check a User Agent in ASP or ASP.NET looks like this:


Checking a User Agent in PHP

To check the user agent in PHP, you check a similar server reference for the HTTP_USER_AGENT - the syntax looks like this for PHP:


What We Do

Our sites have collected over 1,400,000 distinct user agents over the last decade, and we thought this information interesting enough to put on this site. Most of this information is probably only useful to a few people, but that's enough to make it worth putting on the web. Click a user agent category on the right to see some of our user agents categorized, and click any of the user agents or bots in the listing to see more details.


  • Script Injections (349)
  • SQL Injection (7,701)
  • PHP Injection (1,993)
  • XSS Attacks (66)
  • Link Injection (250,869)