Podcastdrill retrieves millions of RSS feeds every month and checks whether their content type is XML before parsing them. However, relying solely on the content-type header doesn’t always work effectively. In this blog post, we will explore commonly used content-types for RSS feeds and identify what major hosting providers are using.
So what kind of content-type is commonly used for rss feed? And what are the hosting providers using?
To answer the first question, Let’s read https://validator.w3.org/feed/docs/warning/UnexpectedContentType.html, to quote:
Feeds should not be served with the ’type/subtype’ media type RSS feeds should be served as application/rss+xml (RSS 1.0 is an RDF format, so it may be served as application/rdf+xml instead). Atom feeds should use application/atom+xml. Alternatively, for compatibility with widely-deployed web browsers, any of these feeds can use one of the more general XML types - preferably application/xml.
Now, let’s see what the major hosting providers are using:
application/rss+xml
- anchor.fm
- art19.com
- libsyn.com
application/xml
- megaphone.fm
- simplecast.com
- omnycontent.com
- acast.com
- captivate.fm
text/xml
- podbean.com
- buzzsprout.com
- spreaker.com
- transistor.fm
- redcircle.com
- feedburner.com
Some smaller providers and self-hosted RSS feeds use incorrect content-type headers, such as application/octet-stream, application/json or text/html. In some cases, the podcast creator may have made a mistake and used the wrong URL for their feed.
Relying solely on the content-type header to identify RSS feeds may not always be effective. While most hosting providers use appropriate content-types, some still use less appropriate ones. It may be necessary to resort to parsing to ensure that a feed is XML.