Is a 180 second video still a YouTube Short? Trim to 179.5 for margin

YouTube's Shorts help page (read 2026-10-08) says a Short can be up to 3 minutes long, which makes exactly 180 seconds fit on a plain reading. The page does not say how YouTube measures the length, whether it rounds, or what happens at 180.04 seconds. If you want a margin, cut to 179.5 seconds: Sume video trim takes a decimal duration from 0.2 to 900, so duration 179.5 is a valid request that costs $0.02.

What is and is not stated

Keep the claims small. The page gives one number for length and one for resolution, and nothing about tolerance. The table separates what the page states from what this post is choosing as a safety margin.

Why a margin helps

A video of 180 seconds on the dot can end up a few frames over when audio and video tracks have slightly different lengths. At 30 fps one frame is 0.033 seconds, so 0.5 seconds is 15 frames of room. The exact length of a container is the longer of its tracks, so the audio track can set it. Giving up half a second removes the question and costs you almost nothing in content.

With precision exact (the default), Sume re-encodes frame-accurately, so duration 179.5 yields about 179.5 seconds. With precision keyframe the cut is a stream copy and can start a GOP early, and the docs say to re-base your times against actual_start_seconds, so the length can differ from what you asked.

The request and the check

Send start and duration with an Idempotency-Key. Then read duration_seconds in GET /v1/jobs/:id/result and compare it with 180 before you upload.

curl -X POST https://api.sume.com/v1/video-trim \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: trim-short-margin-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4",
    "start": 0,
    "duration": 179.5
  }'

If the clip is already cut

For a finished file, you can read its length with video inspect and frames: false, which returns the probe without stills. Video inspect bills probe compute, so the cost is small but not zero; the docs give no flat price for the probe. If the length is over 180, trim again. A larger cut from a 4 minute source is in this post. For variants at several lengths, see the three-cut post.

Why not 179 or 175

A bigger margin works too, and nothing on the page forbids it. The cost of cutting 5 seconds is five seconds of content, while the cost of 0.5 seconds is almost nothing. Pick the smallest margin that removes your doubt, then confirm with duration_seconds in the result.

If you already have a file that is 180.3 seconds, a trim with start 0 and duration 179.5 removes the last 0.8 seconds. Choose the cut point so it lands on a pause in the speech or a natural end of a shot.