How to choose podcast chapter timestamps

Choose the moment a listener would want to hear

At the start of a bicycle repair podcast, the host promises to explain how to find a puncture by listening for a hiss. Fourteen minutes later, she puts air in the tube and demonstrates it. A transcript search for “hiss” can take you to the promise. A chapter called “Finding the leak” should take you to the demonstration. Pick a candidate from the transcript, listen across the transition, then jump straight to it with the previous conversation out of earshot.

Start with the episode file you have permission to publish. Use the delivered edit, including its theme music, credits and any fixed announcements. Write its filename, duration and version above your working list. On an Apple Silicon Mac, you can review timed speech locally in Polyglot and export SRT to keep the cue times beside the words. Keep that file as your reference. Make the chapter decisions in a separate list so revising a jump point leaves the transcript intact.

Audition three possible starts

Imagine a 36-minute episode made by a bicycle workshop. Near the middle, the guest finishes explaining why she removed the wheel. The host then asks how the guest finds a hole too small to see. Air escapes before the guest names the sound. A listener returning to the repair needs the question, the sound and the explanation in that order.

The three spoken lines below are possible starts. The sound between the question and answer explains why the choice matters. These times are invented. Try each spoken start as if you had just tapped the chapter title. At the first time, the listener hears a farewell to the previous topic. At the last time, the explanation makes sense only to someone who already heard the hiss. The question gives the sound a purpose, so use its start. Where a question begins midway through a subtitle cue, listen for the first word and take that playback time. You can leave the cue boundary where it is.

14:11  “The wheel is off.”
14:18  “How do you find
        the hole?”
14:23  [air escapes]
14:26  “Hear that? Here.”

Chosen jump: 14:18
Title: Finding the leak

Write a list someone can scan

Read the proposed titles with the transcript closed. Would a listener with a flat tire know which chapter to tap? “Part two” makes them guess. “Finding the leak” identifies a task. Use the terms listeners hear, and check that the promise of each title holds until the next chapter. If the host mentions tire pressure for fifteen seconds and returns to the patch, the aside can stay in the patch chapter.

For chapters supplied in an Apple Podcasts episode description, Apple asks for the first start at zero and at least three chapters. Its editorial guidance favors short titles and substantial segments. In the fictional episode below, the first chapter includes the introduction and wheel removal. The last begins as the guest starts the patch. The same three lines work as a producer’s sign-off sheet: one person reads the title, another seeks to the time and describes what begins there.

00:00:00 Removing the wheel
00:14:18 Finding the leak
00:25:40 Applying the patch

Carry the same starts into the publishing tool

If your host offers chapter fields, check what units the time field expects. For a host that supplies Apple chapters in the episode description, use the timestamped list. For a host that publishes Podcasting 2.0 chapter JSON, the file uses elapsed seconds and the chapters run in ascending start order. Fourteen minutes and eighteen seconds is 14 × 60 + 18, or 858 seconds. Entering 14.18 in a seconds field would take a listener near the beginning of the show.

Here is the same list as a complete example chapter file. The publisher handles the external file and the episode’s podcast:chapters feed element, whose URL and type identify the resource. Confirm which route your host supports before preparing a file. Polyglot’s SRT export gives you speech and timing to review. You write the chapter titles and prepare the delivery in your publishing tools.

{
  "version": "1.2.0",
  "chapters": [
    {"startTime": 0,
     "title":
       "Removing the wheel"},
    {"startTime": 858,
     "title":
       "Finding the leak"},
    {"startTime": 1540,
     "title":
       "Applying the patch"}
  ]
}

Seek from the published list after an edit

Suppose the producer removes a 12-second workshop announcement from minute 20. The leak demonstration still begins at 14:18. The patch now begins at 25:28, or 1528 seconds. Shifting the entire list would break the middle chapter. Update the affected entry, mark the new master on the working sheet, and listen again at all three starts. A replacement announcement of the same length could leave every timestamp correct while making a title misleading.

In the destination player, open the episode through the listener-facing show page. Read the displayed titles in order, tap the last chapter first, then jump back to the middle and restart at the first. Listen to the first sentence or action after every tap. Compare the episode version and the chapter data if a jump works in your edit but misses in the player. Apple says RSS and description changes appear after its feed refresh. For this edit, the check is complete when tapping “Applying the patch” lands at 25:28 and you hear the guest begin that step.

If different listeners receive edits with different ad lengths, one elapsed time can point to different speech. Ask your host which audio version its chapter times describe and test the version you intend to distribute. Keep the transcript available for listeners looking up a particular word. The chapter list earns its place when someone can skim three titles, choose the repair they need and hear it begin.

Keep exploring.