How to make a YouTube channel trailer with AI

A YouTube channel trailer is a video you choose to greet people who haven't subscribed when they open your channel's Home tab. To make one, write a short pitch (who the channel is for, what you post, and why to subscribe), turn it into a 16:9 video, then set it in YouTube Studio under Customization, Home tab, Layout. With AI, the video can be a talking avatar reading your script, so you don't have to film anything.

YouTube's rules are quoted from its help pages Customize your YouTube channel layout and Video resolution & aspect ratios, read on 2026-09-28. Sume facts come from the Generate avatar video, Create new avatar, and Video captions docs; anything called current code is read from Sume's source.

Who sees a channel trailer?

Only viewers who haven't subscribed, and each of them only until they've watched it once. YouTube describes it as a preview of your channel so viewers can learn more and subscribe. Returning subscribers get a separate slot, the featured video:

How long should a YouTube channel trailer be?

YouTube's channel layout page sets no length for it, so the length is your call. On Sume, one avatar video takes a script it estimates at 4 to 60 seconds, so a trailer of up to a minute is one job; how many words fit in 60 seconds helps you size the script. For a longer trailer, join 16:9 segments as in How to make an AI avatar video longer than 60 seconds. That post detaches each segment's audio first, because in current code a Timeline render takes its sound only from its audio spine, not from the clips.

What should a channel trailer say?

Write it for a stranger who has one question: is this channel for me? A simple order works:

• Who the channel is for, in the first sentence.
• What you post and how often, with one concrete example.
• Which video to watch first.
• One ask at the end: subscribe.

How do I make a channel trailer with an AI avatar?

Create the presenter once with POST /v1/avatar-1.0/generate (Create a reusable AI avatar has the fields), then send its avatar_handle and your script to POST /v1/avatar-1.0/talking-video. AI avatar for YouTube videos covers the rest of the setup; for a trailer, mind these points:

• Set aspect_ratio to 16:9, YouTube's standard aspect ratio on a computer, because the default is 9:16. 720p is the documented resolution.
• Use your own likeness or that of someone who agreed to present the channel.
• Speech is English only in current code: the clip prompt asks for English. For another language, or no presenter at all, narrate over B-roll as in Faceless video API.
• To check the look before paying for the full render, start from a first-frame preview, covered in Avatar video previews.

curl -X POST https://api.sume.com/v1/avatar-1.0/talking-video \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: channel-trailer-v1" \
  -d '{
    "avatar_handle": "channel_host",
    "script": "New here? This channel is for home cooks with twenty minutes on a weeknight. Every Tuesday I post one fast dinner, tested three times. Start with the one-pan lemon chicken, and subscribe for next week.",
    "aspect_ratio": "16:9",
    "quality": "plus"
  }'

How do I add captions to the trailer?

Burn them in with a separate job, so viewers with the sound off can still follow. A completed avatar job can include a public media.sume.com video artifact: send that URL to POST /v1/video-captions with your script as script_text. Speech-to-text keeps the timing and the burned words follow your script. In current code a caption job refuses a video longer than 60 seconds, so caption each segment before you join a longer trailer.

How much does an AI channel trailer cost?

Creating the avatar costs $0.95 per avatar. Avatar video bills per second by quality tier: $0.184/s standard, $0.245/s plus, $0.55/s max (no product image), so a 60-second trailer at the default plus tier is $14.70. Both are plus a 5.5% agent fee by default. A caption job is a fixed amount per video of up to 60 seconds, listed on the Video captions page.

How do I set the video as my channel trailer?

Upload it to your channel first. Then, in YouTube Studio, select Customization, then Home tab; under Layout, click ADD section, then Channel trailer; select the video, and click Publish. The Home tab itself must be turned on, which you do on the same Customization screen.