TikTok API video resolution 360-4096 px: size an AI clip first

TikTok's Content Posting API accepts video whose width and height are each between 360 and 4096 pixels. A 1080 by 1920 vertical clip is well inside that, but Sume's Video trim will let you set an output edge as small as 256, which TikTok's page says is too small. If you conform a clip, pick an edge of at least 360.

The range comes from TikTok's Media Transfer Guide, read on 2026-10-02. The guide states the limit as 360-4096 pixels for both dimensions, and the Get Post Status page lists picture size among the reasons a post fails.

What are the two ranges side by side?

The table below puts the vendor range next to the Sume conform range so the mismatch is visible in one place.

How do you check the clip you already have?

Video inspect reads one clip on media.sume.com and returns probe facts. With frames: false it is a probe-only call with no stills, and the docs say probe and stills are unbilled. Read the probe before you decide whether to conform.

The probe fields themselves are documented as part of the returned probe object, and the docs name probe.has_audio explicitly; read the live response for the dimension fields rather than assuming their names.

curl -X POST https://api.sume.com/v1/video-inspect \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: tiktok-size-probe-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4",
    "frames": false
  }'

How do you resize inside the safe overlap?

Send output with width and height to POST /v1/video-trim, both within 256-2160 by Sume's rule, and keep them at 360 or above for TikTok. The conform needs precision: "exact", which is the default. Omit output to inherit the source size.

A few rules follow from the docs. The source clip must be at most 1800 seconds and the output at most 900 seconds. Both output dimensions and fps are exact-only. Sending precision: "keyframe" with output fails with video_trim_output_requires_exact.

What does Sume not do?

Sume does not post for you, and Video trim does not upscale beyond 2160 pixels, so a 4096-pixel master is outside what it can produce even though TikTok accepts it. For a 4K source you either post the original file yourself or conform it down to 2160 or less.

Aspect ratio is a separate question that TikTok's media guide does not fix in the page read for this post. See social media video sizes for the platform-by-platform view.