Keep a vertical video out of Shorts: render a 16:9 blur-fill cut

Sometimes you want a vertical clip on YouTube as an ordinary video, not a Short. YouTube's three-minute Shorts page addresses a related case, a music claim that blocks Shorts over a minute, and says to use a wider ratio such as 16:9 to avoid being treated as a Short. That is the lever: put the vertical clip inside a 1920x1080 frame. Sume's Timeline does it with fit: "blur".

The advice is in Understand three-minute YouTube Shorts (read 2026-10-03). Upload YouTube Shorts (read 2026-10-03) defines the other side: Shorts are up to 3 minutes and square or vertical. A 16:9 file is neither, so it is a normal upload. Neither page promises a result for every upload, so check the video in Studio after it processes.

Why blur and not cover

A 1080x1920 clip placed in 1920x1080 with the default cover scales to 1920 wide and shows only about 32 percent of its height. That crops out most of a vertical shot. contain keeps all of it but leaves black bars on both sides. blur keeps the whole clip fitted in the centre and fills the rest with a blurred copy, which usually reads as intended.

The render

Timeline 1.0 takes audio.duration_seconds as the output length, so set it to the clip's length. A clip with its own audio goes in as the spine through audio.url. The rate is $0.10 per started output minute, so a 2 minute 10 second video bills three minutes, $0.30.

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: wide-blur-001" \
  -d '{
    "audio": {
      "url": "https://media.sume.com/artifacts/artf_demo/voice.wav",
      "duration_seconds": 130
    },
    "video": [{
      "source_url": "https://media.sume.com/artifacts/artf_demo/vertical.mp4",
      "start": 0,
      "duration": 130,
      "fit": "blur"
    }],
    "output": { "width": 1920, "height": 1080, "fps": 30 }
  }'

What you give up

The vertical clip is small inside a wide frame: at 1080 high, its width is 608 pixels, about 32 percent of the frame. Any burned-in captions shrink with it, so check they stay readable at that size. If the video really is for a phone, a Short may be the better home, and the length limit then matters more than the shape.