Q: Which to implement – RSS or ATOM or Both?

A: If you’re a content-publisher: it does not matter in the slightest. Just pick one that you like. In fact, I think it’s a mistake to implement both. Read on.

There are two main “feed” formats. But here’s the thing – publishers don’t need to support both, readers do. If you’re writing a feed-reader, then sure, you have to support both. But as a content-publisher what’s the point? All readers worth their salt will support both. So just pick the format that you feel will better describe your data and use that one.

There are actually disadvantages in supporting both as a publisher, and that is if you advertise multiple feeds on the same page (e.g. one for RSS and one for ATOM, even though they are identical), the user will often be prompted as to which one they want (see screenshot). This forces the user to choose between two identical outcomes. So what’s the point? I don’t want my Mum asking me which one she should use.

FWIW I favour Atom, I think it’s better formed.

My WordPress theme (and I’m guessing others too) by default advertised 3 feeds. This post was actually sparked by my work onGeospike, not this blog – but I will eat my own medicine here as well. Hence, OmegaDelta now only advertises ATOM. The old feeds will still work, for clients that may have subscribed to them in the past.

On the topic of ATOM feeds, make sure you validate, to improve your chances of the feed working in readers (hint: if it’s not valid, forget about it!)