One 9:16 size for TikTok and LinkedIn ads: 540x960 to 1080x1920

A vertical 9:16 file between 540x960 and 1080x1920 clears both TikTok's non-Spark minimum and LinkedIn's maximum, so one render can serve both ads. TikTok's page lists 9:16 at 540x960 or larger and does not list an upper size. LinkedIn lists 9:16 from 360x640 to 1080x1920, recommending 720x1280 (TikTok and LinkedIn pages, read 2026-10-09). Sume's timeline default of 1080x1920 sits exactly at LinkedIn's upper edge, so it works for both.

The overlap, size by size

The window's lower edge comes from TikTok (540x960) and its upper edge from LinkedIn (1080x1920). Every 9:16 size with a width from 540 to 1080 falls inside it.

Choosing within the window

720x1280 is LinkedIn's recommended size and comfortably above TikTok's minimum, so it is the middle pick. 1080x1920 gives more pixels on TikTok and is allowed on LinkedIn, which makes it the simplest if you never change the default. The timeline price is the same for both: $0.10 per output minute, rounded up, so a 30-second ad is $0.10 either way.

Render once and upload the same file to both. That is $0.10 for the pair, instead of $0.20 for two renders.

What still differs per platform

The sizes line up, but the other rules do not. TikTok lists a bitrate of at least 516 kbps, a 500 MB limit and a 10-minute limit, and accepts .mp4, .mov, .mpeg, .3gp and .avi. LinkedIn takes MP4 only, with H.264 or VP8, a frame rate under 30 FPS, and 3 seconds to 30 minutes. A file that is MP4 and under 30 FPS, such as 24 or 25 fps from Sume's output.fps choices, meets both lists on those points. For frame rate, TikTok's page gives no figure.

Ad length recommendations differ too. LinkedIn recommends 15 to 30 seconds for all placements. TikTok's page lists a maximum of 10 minutes and no recommendation. So pick the shorter of the two if you want to share one cut.

Set it in the request

Send output.width 720 and output.height 1280 (or 1080 and 1920) and output.fps 25 in the timeline render body. If your sources are not 9:16, video[].fit takes cover, contain, stretch or blur; cover is the default and crops to fill. For a 16:9 source cut to vertical beforehand, see the centered-crop post, and for TikTok's other two ratios see the three-ratios post.