YouTube end screens need 25 seconds: lengthen a 20 second clip on Sume

If a clip is under 25 seconds, you can reach the end-screen minimum by rendering it with a held end card on Sume Timeline: set audio.duration_seconds to 25 or more, put the clip first and a still second. The cost is ceil(25 / 60) = 1 minute at $0.10. YouTube's upload help page (read 2026-10-08) says your video must be 25 seconds or longer to add an end screen, and that shorter videos cannot include one. The page does not say anything about Shorts here, so this post makes no claim about them.

The numbers

Everything on the YouTube side comes from one help page. The Sume side comes from the Timeline 1.0 docs.

Building a 25 second timeline

Take a 20 second clip. Use audio.mode silence with duration_seconds 25 if there is no spine, or your voice file cut to 25 seconds if there is one. Slot one is the clip at start 0 and duration 20. Slot two is an end-card image at start 20 and duration 5, with a transition of type fade and duration 0.25 if you want one. A still is accepted as source_url and held static.

Two rules to watch. The first slot must start at 0, and each later start must increase. Coverage can also stop at most 0.5 seconds before the end of the spine, so the last slot should reach the 25 second mark. If a source is shorter than its slot, the job pads or loops it and returns a soft warning, which is not a failure.

Why a held still and not a loop

A 20 second clip looped to 25 seconds would repeat its last 5 seconds from the start, which looks like a stutter. A still end card gives the channel a place for the elements an end screen uses, and it is cheaper to reason about. Plan the render first with POST /v1/timeline-1.0/plan, which is unbilled, and confirm duration_seconds is 25. For a related cold-open edit on the same platform, see this post.

Check the result

After the render, read duration_seconds from GET /v1/jobs/:id/result and confirm it is at least 25 before you upload. Then look at warnings[]. A soft warning such as a padded short source means the job filled a gap for you, which is useful to know if you meant the clip to end where the end card starts.

The 25 second figure is the only length rule the help page gives for end screens. It does not say where in the video the end screen must sit, and this post does not guess. If your clip is 24 seconds, one more second of end card is enough, and the Timeline bill stays at one minute.