Have you ever wondered what your user agent is? Did you also have some sleepless nights because you couldn’t find it out? Now it’s over! Just visit the site http://whatsmyuseragent.com/ and it tells you everything.
Example: my current user agent is
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:11.0) Gecko/20100101 Firefox/11.0
(The image was borrowed from http://whatsmyuseragent.com/WhatsAUserAgent.asp.)
But… should I care about it?
In some cases yes, you should care about your user agent. For instance, if you want to fetch some web pages with a Python script, you can have some troubles. The Python script identifies itself as a Python agent, and some sites simply block them :( But, of course, we cannot be tricked so easily. Just change the default user agent in your Python script and enjoy the free ride :) For more info, refer to this article.
See also http://www.user-agents.org/, which is a searchable database of user-agents as used by browsers, search-engines spiders and crawlers, web-directories, download managers, link checkers, proxy servers, web filtering tools, harvesters, spambots, badbots.
There is also an interesting Firefox plug-in that allows you to change your user-agent.
History of the browser user-agent string (update 20120425)
Have you ever wondered why user-agent strings are a complete mess? Here is the story.
You want to test your connection whether it’s IPv6 (preferred) or IPv4 (old and crusty).
Visit these test sites:
They are also good to figure out your IP address.