YouTube end screen template: a 5–20 second 16:9 outro

A YouTube end screen template has two layers: YouTube Studio's templates, which place up to four clickable elements, and the outro video underneath them, which you make. Make that outro 16:9 and 5 to 20 seconds long: YouTube only lets end screens use the last 5–20 seconds of a video that runs at least 25 seconds, and it allows four elements on standard 16:9 video, while other aspect ratios may have a lower limit.

YouTube's rules are quoted from its help pages Add end screens to videos and Video resolution & aspect ratios, read on 2026-09-28. Sume facts come from the Format catalog, Create a run, and Timeline 1.0 docs, the logo Format's published description, and the Timeline schema in the Sume API reference.

What are YouTube's end screen rules?

Viewers can hide end screens, and YouTube notes that an end screen may not always show, or may show differently than designed. Plan the outro around these rules:

What size should a YouTube end screen be?

The same size as the video, because the end screen is the video's last seconds. YouTube calls 16:9 the standard aspect ratio on a computer and lists 1920×1080 for 1080p and 1280×720 for 720p. If your video isn't 16:9, YouTube says it may allow fewer than four elements, so keep both the video and the outro 16:9.

The end-screen page publishes no pixel boxes for elements: you drag each one into place in the editor, with a grid and “Snap to grid” to help. So a template needs open space, not exact slots. YouTube asks you to leave enough space and time at the end of the video and, if you use a custom image, recommends one at least 300 × 300 pixels.

How do I make an end screen template with AI?

Make the motion with a catalog Format, then set the exact length with Timeline 1.0. The Format sume-logo-motion-design makes “a finished logo motion video that reveals a supplied brand mark”, and its description lists “launch bumpers, and social end cards”. Logo animation API covers the call: the mark goes in attachments, and your brief in instruction, which wins where it disagrees with the Format's private recipe. For an end screen, the brief asks for 16:9 and a mostly empty frame, and you check the layout you get. Animate only a mark you own or have permission to use.

curl -sS -X POST "https://api.sume.com/v1/formats/sume/sume-logo-motion-design/runs" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: channel-end-card-v1" \
  -d '{
    "instruction": "16:9 end card, about 6 seconds. Reveal the attached logo in the top-left corner and keep the rest of the frame plain and dark for YouTube end-screen elements.",
    "attachments": [
      { "type": "input_image", "image_url": "https://example.com/channel-logo.png" }
    ],
    "generation_spend_cap_usd": 20
  }'

How do I make the outro exactly 20 seconds long?

Put the Format's video, its primary_output_url on media.sume.com, in one Timeline slot as long as the end screen and set render.pad_mode to freeze. When a slot is longer than its source, freeze holds the last frame and loop replays the source. Set output to 1920×1080, since the default frame is 1080×1920.

• A video of another shape is placed by the slot's fit: cover (the default), contain, stretch, or blur.
• audio.mode: "silence" declares the length without a voice track. For music, add a Sume-hosted soundtrack, such as a track from POST /v1/music-router/generate, and set its gain_db to 0: the default of −16 dB is a bed level under a voice.
• Every URL must already be your workspace's media.sume.com file, and Idempotency-Key is required.
• In current code a render's sound comes only from its audio spine and soundtrack, so any sound in the Format's video is dropped.

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: end-screen-outro-20s-v1" \
  -d '{
    "audio": { "mode": "silence", "duration_seconds": 20 },
    "video": [
      { "source_url": "https://media.sume.com/artifacts/artf_demo/end-card.mp4", "start": 0, "duration": 20 }
    ],
    "soundtrack": { "url": "https://media.sume.com/artifacts/artf_demo/outro.mp3", "gain_db": 0, "loop": true, "fade_out_seconds": 3 },
    "output": { "width": 1920, "height": 1080 },
    "render": { "pad_mode": "freeze" }
  }'

How do I add the outro to my video?

Timeline reads only your workspace's media.sume.com files, so for footage you filmed, download the outro and put it at the end in your own editor. If the main video was made on Sume too, it can go before the outro in the same Timeline render, with its sound as the spine, since the clips' own audio is dropped; How to add a voiceover to a video and keep its sound shows how to detach it. Keep the finished video at least 25 seconds long.

Then, in YouTube Studio, open the video from Content, select Editor, then End screen, and add elements or apply a template. Line each element up with the open space in your outro.

What does it cost?

Timeline is listed at $0.10 per output minute and reserves whole minutes, so a 20-second outro reserves one. A music track is $0.125 per audio. Both are plus a 5.5% agent fee by default. The Format run's generation is metered at API pricing rates and capped by generation_spend_cap_usd (up to $500), and usage.debited_usd_micros on its receipt is the full cost, the agent's own turn included.