How to make a YouTube Shorts series: seasons and episodes

To make a YouTube Shorts series, put only Shorts in a playlist, turn the playlist into a show in YouTube Studio, and give every video a season number. Each Short must be portrait or square and at most 180 seconds long.

Rules below are from YouTube's help page Create shows from your videos and its Made on YouTube announcement, both read 2026-09-29. The Sume part is from the Timeline 1.0 docs.

What is a Shorts series?

YouTube describes it as episodic content built entirely for short vertical videos. A viewer who finds an episode in their feed sees a "watch series" button that opens a series feed, where they swipe or use arrows to move to the previous or next episode. The channel page shows a series as one thumbnail.

YouTube's announcement says Shorts series started rolling out to creators on web, mobile and TV on the day of the announcement, with custom thumbnails and sequential playback.

What are the rules for a Shorts series?

YouTube's page lists these conditions for packaging Shorts into an episodic series.

Serial or non-serial: which order do episodes play?

YouTube offers two modes when you add show features to a playlist. Non-serial is the common one: episodes can be watched in any order and are listed newest to oldest. Serial is for episodes meant to be watched in order and lists them oldest to newest. Converting a playlist selects non-serial automatically.

If you set the playlist order by hand, episode numbers follow it. Otherwise they follow publish date, oldest first.

How do I render matching episodes with Sume?

A series works best when every episode has the same shape. Sume's Timeline 1.0 renders one MP4 per call, 1080x1920 by default, from an audio spine of 1 to 1,800 seconds and 1 to 200 video slots. Keep audio.duration_seconds at 180 or less and the episode fits YouTube's limit. Send the same output in every call so all episodes match.

Timeline inputs must already be this workspace's media.sume.com files, for example clips from earlier Sume jobs, and the call needs an Idempotency-Key. The audio is one spine plus an optional soundtrack bed.

curl -X POST https://api.sume.com/v1/timeline-1.0/render \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: series-s1e01" \
  -d '{
    "audio": {
      "url": "https://media.sume.com/artifacts/artf_demo/voice.wav",
      "duration_seconds": 45
    },
    "video": [
      { "source_url": "https://media.sume.com/artifacts/artf_demo/a.mp4", "start": 0, "duration": 45 }
    ],
    "output": { "width": 1080, "height": 1920, "fps": 30 }
  }'

What does this not cover?

Sume renders the files; you create the show and add the episodes in YouTube Studio. For a story-driven series, see Can AI make a video from a story?. For how YouTube decides what counts as a Short, see YouTube Shorts video specs.