UserAgents.io
What does it do?
UserAgents.io provides a simple way to parse a user agent and get technical information about it. The database is updated daily and easy to navigate.
What is an user-agent?
The User-Agent request-header field contains information about the user agent originating the request.
This is for statistical purposes, the tracing of protocol violations, and automated recognition of user agents for the sake of tailoring responses to avoid particular user agent limitations.
User agents SHOULD include this field with requests. The field can contain multiple product tokens and comments identifying the agent and any subproducts which form a significant part of the user agent. By convention, the product tokens are listed in order of their significance for identifying the application.
Source: RFC 2616