FLUX 3 Video 4K uhd (3840x2176) and which Sume video models do 4K

FLUX 3 Video's uhd resolution is 3840 x 2176 at 16:9, and qhd is 2560 x 1440. Sume has no FLUX 3 Video id in its docs. For a 4K clip on Sume, pick a video model whose supported_resolutions includes 4K; the Video Router docs list gemini-omni-flash-1.1 at 3 to 10 seconds in 360p, 720p, 1080p or 4K, 16:9 or 9:16, with native audio.

Black Forest Labs' numbers are from its release notes; Sume's from the Video Router and Video generation docs, read 2026-10-01.

What did BFL add to FLUX 3 Video?

resolution on POST /v1/flux-3-video now takes qhd and uhd alongside hd and fhd. The notes say each class above hd runs the same generation and differs only in the canvas the video upsampler renders. Listed rates for uhd are $0.80 per second for text to video and image to video, and $0.95 per second for video continuation.

Which Sume models list 4K?

Resolution support is per model, not global. The docs name the 4K-capable gemini-omni-flash-1.1, and say minimax-h3 is native 480p or 768p with 2K and 4K upscales priced if requested. Always read supported_resolutions from the catalog for the model you plan to call.

How do I request 4K?

Send resolution: "4K" to a model that advertises it, on the Video Router. The 4K value is accepted only where the model lists it.

curl -X POST https://api.sume.com/v1/video-router/generate \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: video-4k-001" \
  -d '{
    "model": "gemini-omni-flash-1.1",
    "prompt": "A slow dolly shot along a rainy neon street",
    "resolution": "4K",
    "aspect_ratio": "16:9",
    "mode": "async"
  }'

What if the model tops out below 4K?

Generate at a supported size, then use a separate upscale step. Sume's catalog entries differ, so compare video upscale limits and the per-second numbers in FLUX 3 price vs Sume pricing lookup before you pick a route.