Despite its relatively simple nature, RSS is poorly implemented by many tools. This validator is an attempt to codify the specification (literally, to translate it into code) to make it easier to know when you're producing RSS correctly, and to help you fix it when you're not.

The validator also supports the IETF standard Atom format for syndicated feeds, and KML.

There are validators for other web technologies, such as HTML, CSS, and accessibility guidelines, and these have all proven quite popular. As personal news syndication is becoming more widespread, we saw a need for a comprehensive but easy-to-use validator for syndicated feeds.