Longest ad video: Pinterest 15 min, LinkedIn 30 vs Sume 900 s trim

Sume can produce video as long as 15 minutes from a trim and 30 minutes from a Timeline render. That covers Pinterest ads (15 minutes), LinkedIn Pages video (10 minutes) and LinkedIn video ads (30 minutes), but only Timeline reaches the LinkedIn ad ceiling. Trim output stops at 900 seconds, exactly 15 minutes. The platform numbers below were read on 2026-10-08.

The ceilings

LinkedIn's Pages specification gives 3 seconds to 10 minutes for Pages video. Its video ads page gives 3 seconds to 30 minutes. Pinterest's ad specification gives 4 seconds to 15 minutes. On the Sume side, trim takes a source up to 1,800 seconds and writes an output of 0.2 to 900 seconds. Timeline takes an audio spine of 1 to 1,800 seconds.

Which tool to choose

Use trim when you cut a range from one source and want the file nearly as is. It is $0.02 per job. Use Timeline when you join several sources or add audio: it is $0.10 per output minute, rounded up, so a 30-minute render is $3.00. Timeline's cap is on the audio spine, so a 30-minute ad needs a spine of 1,800 seconds or less.

The upload cap is a separate limit. LinkedIn video ads allow up to 500 MB, so a 30-minute file has to average about 2.2 Mbps or less (500 MB is about 4,000 megabits, over 1,800 seconds). Sume has no bitrate field, so the size follows from the encoder defaults; probe the finished file with video inspect and read size_bytes before upload.

A quick check

After either job, read duration_seconds and size_bytes from the result and compare them with the platform line. For long ads the file size is more likely to fail than the duration. If it is too large, cut the length, because Sume offers no codec or bitrate controls and rejects ffmpeg-style fields with ffmpeg_fields_rejected.

{
  "video_url": "https://media.sume.com/artifacts/artf_demo/webinar.mp4",
  "start": 60,
  "duration": 900,
  "precision": "keyframe"
}

When length is not the problem

Most ad videos are far shorter than any of these ceilings. Pinterest recommends 6 to 15 seconds for ads, so a 900-second output is something you mostly need for a webinar, a demo or a product tour. For those, the common workflow is a trim of the longest useful stretch, followed by a probe for size.

Trim has a second mode that matters for long files. precision: keyframe stream-copies the source, so it is faster and does not re-encode, but cuts land on keyframes. precision: exact re-encodes to H.264 MP4 and is frame-accurate. For a 15-minute cut, check the result's size_bytes against the platform cap either way.