LinkedIn video ad ratios: 16:9, 1:1, 4:5, 9:16 pixel sizes, one table

LinkedIn video ads take four ratios: 16:9 at 1920x1080, 1:1 up to 1920x1920, 4:5 with 720x900 recommended, and 9:16 with 720x1280 recommended and 1080x1920 as the maximum. Files must be MP4 with H.264 or VP8 video at under 30 fps, per LinkedIn's video ad specs read on 2026-10-03.

Specs by ratio

The table below keeps only what the LinkedIn page states. Length and file size apply to every ratio.

Rules that apply to every ratio

LinkedIn lists a file size range of 75 KB to 500 MB and a length of 3 seconds to 30 minutes, with 15 to 30 seconds recommended and in-stream placements running to 90 seconds. The container is MP4. Frame rate must stay under 30 fps. Captions are supplied as SRT text only.

• File size: 75 KB to 500 MB.
• Length: 3 s to 30 min; 15-30 s recommended.
• Codec: H.264 or VP8; frame rate under 30 fps.
• Captions: SRT text file only.

Matching each ratio on Sume

Sume's video generation page lists the aspect ratios the API knows: 16:9, 9:16, 1:1, 4:3, 3:4, 3:2, 2:3, 21:9 and 9:21. A given model supports only a subset, reported in supported_aspect_ratios from GET /v1/videos/models.

The docs example for seedance-2 lists 21:9, 16:9, 4:3, 1:1, 3:4 and 9:16, with no 4:5. That is the gap to plan for. For a 4:5 placement, read the model list for a model that advertises it before you commit, or choose 1:1 or 9:16 for that placement instead of forcing a ratio the model rejects.

Frame rate is the field to watch

LinkedIn's under-30 fps rule matters when you assemble clips. Sume's Timeline 1.0 accepts output.fps of 24, 25, 30 or 60, and when you omit it the render follows the source rate. A 30 fps render would sit at the LinkedIn limit rather than under it, and 60 clearly breaks it, so set 24 or 25 explicitly on timeline renders meant for LinkedIn. Verify the rate on the delivered file rather than trusting the request.

{
  "output": {
    "width": 1080,
    "height": 1920,
    "fps": 25
  }
}