Apple recently released publication guidelines for podcasters. As an organisation, they’ve done good work in advancing the standard and popularising the format, with its apps. But in my opinion, they’ve overstepped the mark with their “strong” recommendation to use the AAC file format instead of the widely-accepted standard, MP3. Here’s why I think that’s problematic, and why it’s not something we, Podiant, will be supporting.

No one player gets to change the rules of the game

While Apple aren’t trying to dominate or own the landscape of podcasting, with this recommendation, they’re trying to heavily skew it in their favour, because it’s technology they prefer. They added extra features to GarageBand — back when it still supported podcasting as an on-label use — to allow easy creation of chapter markers and in-chapter artwork for AAC, while standards for the same within MP3 lagged behind. What this led to, in podcasting’s early years, was a split between a “standard” feed that would play anywhere, and an “enhanced” feed that would only play on iPods, and later iPhones. That’s confusing for the listener, expensive for the creator.

I believe it simply isn’t up to one company to decide which file format is best. They can, and do, offer up suggestions for additions to RSS feeds, but suggesting a different format is a much bigger deal. (As a quick aside to this anyone can suggest an addition to RSS; it’s just up to apps and directories to figure out which to adopt. I love that about this community.)

Open vs closed

Although AAC is a patented technology — unlike MP3, whose patent has not been renewed — there aren’t too many technical barriers to creating AAC files (there are some, but that’s a little out-of-scope for here), but it’s harder to work with them when you’re creating a player (either software or hardware), and companies that like to be able to stitch MP3 content together will find it more difficult, as it’s a much less forgiving medium than MP3. MP3 also has lots of well-documented standards and tools that work within those standards.

To that point: Apple typically likes closed systems. Podcasters — especially those who nerd out around formats and bitrates — typically like open systems (see above my aside about RSS). Podcasting was built on open systems, and although at the time of podcasting’s inception, MP3 was technically closed (because of the patent), it was, and is, far easier to work with as a file format than AAC.


When I first built Podiant, I made a conscious decision that it shouldn’t matter — within reason — what format you uploaded your audio in, because it would always come out the same. I chose MP3 as the destination format because I knew that, without fail, it would be playable anywhere, on any device, be it an Android smartphone from five years ago or a Creative Zen that’s just been dusted off. To me, that counts for something.

I want everyone’s content to be heard everywhere, not just on Apple devices. MP3 isn’t the best format for that, but neither is RSS the best format for syndicating podcast content. We’re stuck with these formats, but it’s not about what’s the best in isolation. MP3 is supported everywhere , and for now, AAC just isn’t. MP3 files are easier to encode, edit and decode; AAC is harder, and it’s still patent-encumbered.


I’m not saying Podiant won’t ever offer other audio formats. I’m just saying that we’re highly unlikely to switch from the ubiquity of one format to the partial support of another, especially on the recommendation of one company.