A well-recorded and well-mixed episode is only halfway there. To reach listeners it must be exported in the right format, accompanied by correct metadata and published in an RSS feed that podcast apps can read. These are simple technical steps, but a mistake at this stage can make an episode invisible or hard to listen to.
Exporting the episode
The master
Before the final export, it is wise to save an uncompressed master, for example a 24-bit, 48 kHz WAV, with loudness and true peak already checked. All compressed versions are made from this file. If a different version is ever needed, you start from the master and not from an MP3.
The file to publish
For distribution, MP3 remains the format most compatible with podcast apps. Reasonable settings for a spoken podcast:
| Parameter | Indicative value |
|---|---|
| Format | MP3 |
| Channels | Mono for speech only, stereo if music is central |
| Bitrate | 64-96 kbps mono, 128 kbps stereo |
| Sample rate | 44.1 or 48 kHz, consistent with the project |
Some platforms also accept AAC files; the choice depends on the hosting platform and its guidelines.
ID3 metadata
MP3 files can contain descriptive information in ID3 tags. Apps rely mainly on feed data, but tags are useful when the file is downloaded and played outside the app. The main fields:
- Title of the episode;
- Artist or author, meaning the podcast's or host's name;
- Album, usually the podcast's name;
- Track number, handy for the episode number;
- Year and genre;
- embedded artwork.
Keep the embedded artwork at a reasonable size: a huge image inside every file needlessly bloats the download.
Chapters
Chapters split the episode into sections with a title and start time, and sometimes an image or a link. Listeners can jump straight to the topic they care about. There are two approaches:
- chapters embedded in the file via ID3 tags;
- chapters in a separate file, referenced in the feed, supported by several recent apps.
Support varies across apps, so it is also useful to list the chapter times in the episode's text description.
The RSS feed
The RSS feed is an XML file that describes the podcast and its list of episodes. Apps check it periodically and download new episodes as they appear. Here is a basic outline of a single episode:
<item>
<title>Episode 12: recording at home</title>
<description>How to improve a room's acoustics.</description>
<enclosure url="FILE-ADDRESS/episode-12.mp3"
length="38500000" type="audio/mpeg"/>
<guid isPermaLink="false">podcast-ep-012</guid>
<pubDate>Tue, 03 Mar 2026 08:00:00 +0100</pubDate>
</item>
The key elements:
- enclosure: the audio file's address, its size in bytes and its MIME type. No enclosure, no episode.
- guid: a unique, permanent identifier. Apps use it to recognize an episode they have already downloaded. If it changes, the episode reappears as new for every subscriber.
- pubDate: the publication date in the format required by the RSS standard.
At the level of the whole podcast, the feed contains title, description, language, artwork, author and category. The main podcast directories add their own fields through extensions to the standard, and set specific requirements, for example on the minimum artwork size.
Common mistakes
- Changing the guid when replacing a file: the episode gets duplicated in subscriptions.
- Replacing the file but keeping a wrong length: some apps show incorrect durations or stop the download.
- Moving hosting without redirecting the feed: subscribers stop receiving episodes. Platforms provide redirect procedures that must be followed carefully.
- Artwork with tiny text: apps display it very small, so titles and lettering must stay readable at reduced sizes.
In my work, before announcing a new episode, I check the feed with a validator and open it in at least two different apps: it is the quickest way to spot problems with the enclosure, date or artwork.
In short
- Keep an uncompressed master and derive the distribution files from it.
- Mono MP3 at a moderate bitrate suits most spoken podcasts.
- ID3 tags and chapters improve the experience, but support varies across apps.
- In the RSS feed, enclosure, guid and pubDate are the essential elements of every episode.
- Never change the guid: check the feed with a validator before publishing.
