LinkedIn video minimums 360x360, 360x450, 360x640: Sume floor is 256

LinkedIn lists a minimum size for each ratio: 640x360 for 16:9, 360x360 for 1:1, 360x450 for 4:5 and 360x640 for 9:16. Sume lets you set output sizes down to 256 on each side, so Sume will not stop you from rendering a file LinkedIn's page says is too small. Check the size you pass in output against the table below before you render (LinkedIn page and Sume docs, read 2026-10-09).

LinkedIn minimums and maximums

The LinkedIn page gives these ranges for video ads. The maximum column matters as much as the minimum, because the same page caps each ratio.

What Sume allows

For both timeline output and trim output, the Timeline 1.0 and Video trim docs give width and height as 256 to 2160, with even values for the timeline. So 320x568 is a legal Sume size and an illegal LinkedIn size. Sume does not know which platform you are targeting; it validates only its own range.

This matters mostly for drafts. A common habit is to render a small 9:16 preview for quick review. A 270x480 preview is fine for review, but it is below the LinkedIn minimum of 360x640, so it is not an upload candidate.

Rendering to a LinkedIn minimum

You rarely want the minimum, but you may want something close for a throwaway test of the upload flow. These are even and legal in both systems: 640x360, 360x360, 360x450 and 360x640. All four are exactly the LinkedIn minimums, and each is above Sume's 256 floor.

You can also lean on the free checks Sume already has. The timeline plan returns duration_seconds, segment_count and billable_minutes without creating a job, which is enough to confirm the length and cost before you spend anything. Only the LinkedIn size window needs your own guard.

A guard to add

The cheap fix is a lookup in your own code. Keep a small table with the minimum and maximum per ratio, and check output.width and output.height before you call the render. An unbilled plan call tells you the document is valid for Sume, but it knows nothing about LinkedIn's limits. For the 3-second length floor on the same page, see the shortest ad lengths post. For a first crop to the right ratio, see centered crop fractions.