Feed Preview is a Firefox addon designed to enhance user experience by indicating RSS or Atom feed availability directly in the browser's URL bar. It offers a unique combination of features, including extensive feed format support for various RSS and Atom versions, allowing users to easily access and preview feeds. The addon also supports non-UTF-8 character sets and employs content sniffing to detect feeds, ensuring a seamless experience when navigating different types of content.

In addition to its robust parsing capabilities, Feed Preview allows users to subscribe to feeds using customizable web-based feed readers, with presets for popular services. The addon ensures secure content display through sandboxed iframes and sanitizes all other elements. With a modern design that adheres to the Photon guidelines, it integrates smoothly with Firefox. Open-source and fully internationalized, Feed Preview also welcomes user-submitted translations, making it a versatile tool for feed enthusiasts.