LinkedIn in-stream pairing rule: which masters to render and the cost

For LinkedIn's in-stream placement, the page says horizontal video pairs with horizontal, vertical with vertical, and square with either. So a square master is the safest single file, and a horizontal plus a vertical master covers the rest. On Sume, each master is one timeline render at $0.10 per output minute, rounded up.

What LinkedIn says about in-stream

The in-stream length is up to 90 seconds and LinkedIn describes it as in testing, so confirm in the Campaign Manager before you build a plan around it. Recommended length for other video ads is 15 to 30 seconds.

The table summarizes the page as read on 2026-10-08.

Render plan on Sume

Timeline 1.0 defaults to 1080 x 1920. You can set output.width and output.height to any even integers from 256 to 2160, so 1080 x 1080 and 1920 x 1080 are both valid. Each render is priced at $0.10 per output minute, rounded up to the next whole minute.

Watch the 61 second cliff

A 61 second ad rounds up to two minutes, so it costs 2 x $0.10 = $0.20 per master, and three masters cost $0.60. Trimming one second to land on 60 seconds halves the price. A 90 second in-stream ad costs $0.20 per master, so $0.60 for the three.

Use fit to decide how a different shaped source fills the frame: cover crops, contain letterboxes, blur fills the sides with a blurred copy. Fit is set per slot. The sketch shows one slot, 60 seconds, at 1080 x 1080.

• 60 seconds or less: $0.10 per master.
• 61 to 120 seconds: $0.20 per master.
• Use the unbilled /plan call to check the compile before you pay for a render.

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: square-master-001" \
  -d '{"audio":{"mode":"silence","duration_seconds":60},"video":[{"source_url":"https://media.sume.com/artifacts/artf_demo/ad.mp4","start":0,"duration":60,"fit":"cover"}],"output":{"width":1080,"height":1080}}'

Which to render first

If you only run in-stream, render the square master first because it pairs with either. Add the others only when your placement report shows the pairing is limiting delivery. That decision is yours; Sume only renders the files.

The /plan endpoint compiles a timeline request without billing it. Use it to confirm that slot durations add up to audio.duration_seconds and that your output size is accepted before you pay for the render. Nothing in this post depends on it, but it removes the guesswork from the $0.10 versus $0.20 decision at the minute boundary.

If the plan comes back with a warning about padded or looped short sources, fix the source rather than the settings: a short clip stretched over a long slot is the usual cause.