What is GUID?
A GUID (Globally Unique Identifier) is a permanent, unique identifier assigned to each episode in your RSS feed. Podcast apps use GUIDs to track episode identity across feed updates, migrations, and metadata changes.
How GUIDs Work
<item>
<title>Episode 42: The Answer</title>
<guid isPermaLink="false">podcast-show-ep-042-2024</guid>
<!-- Other elements -->
</item>
When a podcast app checks your feed, it compares GUIDs to determine:
- Which episodes are new (download them)
- Which episodes exist (skip downloading)
- Which episodes the user has already played (maintain progress)
GUID Best Practices
| Practice | Reason |
|---|---|
| Never change GUIDs | Changing triggers re-downloads for all subscribers |
| Make them truly unique | Duplicates cause unpredictable behavior |
| Use stable identifiers | UUIDs, database IDs, or structured strings work well |
| Keep them after migration | Preserve GUIDs when changing hosts |
Common GUID Formats
UUID format:
<guid isPermaLink="false">550e8400-e29b-41d4-a716-446655440000</guid>
Structured format:
<guid isPermaLink="false">mypodcast-episode-42-2024-01-15</guid>
URL format (legacy):
<guid isPermaLink="true">https://example.com/episodes/42</guid>
The isPermaLink attribute indicates whether the GUID is a valid URL. Modern practice uses isPermaLink="false" with non-URL identifiers.
What Happens When GUIDs Change
If you accidentally change an episode's GUID:
- Mass re-download: Every subscriber downloads the episode again
- Lost progress: Listening position resets to the beginning
- Duplicate entries: Some apps show the episode twice temporarily
- Analytics confusion: The "new" episode gets separate download counts
Why It Matters
GUIDs are the invisible glue that maintains your listeners' podcast experience. While they never see GUIDs directly, any problems with them create immediate, frustrating issues.
Why GUID stability is critical:
-
Listener experience: Nobody wants to re-download episodes they've already heard or lose their playback position in a 2-hour episode.
-
Storage management: Re-downloads waste listener bandwidth and storage, especially painful for mobile users with limited data plans.
-
Analytics integrity: Download metrics become unreliable when the same content gets counted multiple times under different GUIDs.
-
Host migration: When migrating between hosting providers, preserving GUIDs is essential to maintaining continuity.
The GUID golden rule: Once an episode is published, its GUID should never change—even if you:
- Update the episode title
- Fix a typo in the description
- Replace the audio file
- Change hosting providers
- Modify the publication date
All of these changes are fine. Changing the GUID is not.
How to Use This in Dispatch
GUIDs are automatically generated when you create episodes and remain permanently stable:
Automatic GUID generation:
- Unique identifier created at episode creation
- Never changes regardless of edits
- Preserved during audio file replacements
- Maintained if you export/import your podcast
Migration protection: When importing a podcast from another host, we preserve your original GUIDs to ensure subscribers don't experience re-downloads.
What you can safely change:
- Episode titles
- Descriptions and show notes
- Audio files (enclosure URL updates, GUID stays)
- Publication dates
- Categories and tags
All these changes propagate to apps without triggering re-downloads because the GUID remains constant.