Gemini Omni Flash 4K for a YouTube Short: what the extra $1.875 buys

On Sume, a 10-second 9:16 Gemini Omni Flash 1.1 clip costs $1.875 at 1080p and $3.75 at 4K, so 4K adds $1.875 per clip. For a YouTube Short that is mostly wasted: YouTube lists 1080p as the maximum upload resolution for Shorts (read 2026-10-09).

Gemini Omni Flash went GA on 2026-08-27 per the Gemini API changelog (read 2026-10-09). Sume's catalog entry accepts 3 to 10 seconds at 360p, 720p, 1080p and 4K in 16:9 or 9:16.

The two caps that stack

First, Shorts: vertical, up to 3 minutes, 1080p maximum. Second, Timeline: output width and height are even integers from 256 to 2160, and the default output is 1080x1920. A vertical 4K frame is 2160x3840, which does not fit under the 2160 per-edge limit, so a 4K vertical clip cannot pass through Timeline unscaled.

When 4K can still be the right call

Use 4K only when the clip leaves Timeline: a still frame you pull from the video, a crop-and-reframe done elsewhere, or an archive master. If the final file is a Short, the 1080p row is the ceiling that matters.

The gap on a full minute is $11.25 ($22.50 versus $11.25), before the $0.10 Timeline minute.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"gemini-omni-flash-1.1","prompt":"Scene 1 of 3: ...",
   "aspect_ratio":"9:16","resolution":"1080p","duration":10}'

Gotchas

• The resolution string for 4K is written 4K in the catalog; check GET /v1/videos/models before you send it.
• Omni Flash 1.1 takes image and video references but no audio reference; native audio is on by default.
• Do not set output.width and output.height above 2160 in Timeline; both are capped there.