A full test: how do show notes display in podcast apps?

This article is from 2019 and is out of date. We’d recommend reading Transistor’s test from May 2024 instead.

Episode notes are an important part of a podcast. In some cases, episode notes link to more information about things mentioned within the podcasts. They often contain credits for material used: mandatory credits, sometimes, if using Creative Commons licences. They can contain advertiser links. They regularly contain links for supporting a podcast financially, like Patreon links. They’re a vital part of podcasting.

But: how do episode notes display in different apps? And if you want to use show notes properly, what should you avoid?

Here’s the specification

In December 2019, we established how to do episode notes. The RSS specification says that you use two tags in RSS:

• <content:encoded> contains HTML episode notes
• <description> should only be text, not HTML

Podcast apps that handle HTML episode notes - most of them - will use the information in <content-encoded>, and will ignore the <description> altogether.

Podcast apps that don’t handle HTML episode notes will correctly ignore <content:encoded> and, instead, will use the text-only <description> field.

Unfortunately, many podcast hosts don’t correctly set these fields in RSS.

Here’s how podcast apps cope

We used this episode of Podnews to produce a special version of our podcast for this test. Thanks to the generosity of our readers, we were able to test 19 elements (below), in over 40 different apps.

While no app got a perfect score, the best apps for displaying shownotes were PocketCasts, Overcast and Castro, who each passed the highest number of our individual tests.

71% of all apps displayed our test show notes in full, without truncating them. Only 60% of podcast apps supported web address links in show notes, which was disappointing, especially for podcasts who rely on donations for revenue.

Only 14% displayed the iTunes Summary field somewhere; and only 12% showed an episode number, echoing our research earlier this year. We didn’t take this opportunity to measure support for chapter points, but last we checked, we concluded that it wasn’t worth the time.

There are many different podcast apps, of course: but according to Libsyn, only eight podcast apps are popular enough to be responsible for more than 1% of all podcast downloads. We plugged in Libsyn’s most recent numbers into our list, so we could work out what most people see.

From this list, Stitcher is the only app that does not follow the specifications (erroneously stripping the HTML out of content:encoded). Stitcher and Spotify do not support HTML episode notes, but Spotify correctly uses the description field.

You can also see our test results in full.

Our recommendations

• Use content:encoded for your HTML, and write a text version in description. This is the most sure-fire way to ensure your podcast episode notes display the way you want them.
• Embedded images will be discarded by most podcast apps, so make sure you don’t need to rely on them.
• Don’t try to style or format your text: your attempts will fail. The only exception is an unordered list, like this one, which will show to 86% of all listeners.
• For accented characters we would recommend using standard unicode in your RSS feeds, rather than any form of HTML entities. Just write an é; don’t write é or é.
• iTunes summaries, a really useful sentence or two about what this episode is all about, are supported by a disappointing amount of apps; but those apps that do support it means 78% of all listeners will see them.

We’d also recommend not to let this list hold you back. Do whatever you like in show notes: some of the best podcast apps will display them just fine. Just make sure they degrade gracefully in the apps where they don’t.

Our tests

• An embedded image (800px wide jpeg)
• Accents (in unicode, like é)
• Accents (in HTML entity, like é)
• Accents (in a numeric code, like é)
• Paragraphs (<p> tags)
• italics (using <em>)
• bold (using <strong>)
• An unordered list (<ul>)
• An ordered list (<ol>)
• A blockquote
• A naked HTML link
• An “a href” HTML link
• A raw email address (clickable)
• The <code> tag
• A <center> tag
• Small text
• A donation link using rel="payment"
• A separate itunes:summary
• A visible episode number
• Displays in full (not truncated)

We’re not suggesting, by the way, that the above is a full list of things we’d like to see in podcast apps. Accented characters are mandatory, we’d think, but being able to display an image probably isn’t. This list represents what is possible to display, rather than a suggestion of any standard.