LinkedIn video ads: the first 10 seconds and a frame check with Sume

LinkedIn's video ad page says to put the most impactful content in the first 10 seconds. To check that, pull stills at a handful of times in those 10 seconds with Sume video frames and look at them with the sound off. The call takes up to 24 times, outputs jpeg or png, and is billed as Modal compute rather than a fixed price.

What LinkedIn says about playback

Three statements on the page affect how you cut the opening. They were read on 2026-10-08.

Pull the frames

Send at as a list of seconds, each at least 0 and less than the clip duration. A time past the end fails with frame_time_out_of_range and returns the probed duration. The source can be up to 300 seconds. If you would rather sample evenly, send fps up to 2 instead; the two options are exclusive.

This request asks for seven stills across the first ten seconds.

curl -X POST https://api.sume.com/v1/video-frames \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: li-open-check-001" \
  -d '{"video_url":"https://media.sume.com/artifacts/artf_demo/ad.mp4","at":[0,1,2,3,5,7,9.5],"format":"jpeg","max_edge":720}'

What to look for

A viewer often sees a feed video without sound at first, so the frames should make sense on their own. Check each still against a short list.

• Frame 0: is the subject or the product visible, with no black or logo-only opener?
• Frames 1 to 3: does the message appear in text or in clear action?
• Frame 5 and later: has the offer or call to action appeared before second 10?
• Last frame: does it end on a clean card that works when the video loops?

Fix what you find

If the message is not visible without sound, burn it in. Video captions takes cues with text, start and end and costs $0.20 per job for videos up to 60 seconds. Because LinkedIn loops a video under 30 seconds to at least 30 seconds of playback, a last frame that cuts mid-sentence will be seen again and again, so end on a full stop.

Re-run the frames call on the new file. It costs only compute, so checking twice is cheap. Keep the first request as a template: only video_url and the Idempotency-Key change between versions of the cut. If you cut several versions, name the keys after the version so a retry does not create a duplicate job. Comparing the same seven times across versions shows quickly which opening carries the message soonest.