Seedance 2.5 test clip: 4 s at 480p is $1.07 on Sume, $0.80 on Runway

The cheapest honest Seedance 2.5 test is a 4-second clip at 480p, which costs $1.07 on Sume (4 x $0.268677 = $1.074708) and $0.80 on Runway Dev (4 x 20 credits = 80 credits, which is also Runway's stated per-generation minimum). Sume's docs give 4 to 30 seconds as the valid range, and the shared price sheet notes a minimum billed length of 4 seconds.

Runway also charges 10 credits per second for input and reference video on its 480p row, while reference images and audio are free; Sume's figures here are output-second list prices at default options, so a request with video inputs needs its own estimate.

Three resolutions, one 4-second floor

Runway's seedance2_5 rows are 20, 30 and 68 credits per second of output at 480p, 720p and 1080p. At $0.01 per credit, 4 seconds is 80, 120 and 272 credits.

Reading the ratios

Unlike Wan, where Sume sits at a flat 1.25x of Runway, Seedance 2.5 on Sume costs more than Runway Dev at every resolution, and the gap widens as resolution rises. I do not know how the two vendors source the model, so treat the ratio as a fact about published prices, not a claim about cost.

The practical read: if a test clip is the only goal and you already hold Runway credits, Runway is cheaper at every tier. If the clip is one step in a Sume pipeline (a timeline render, TTS, captions), the extra dollars buy a single balance and one job model.

Submitting the 4-second test on Sume

Send the shortest valid duration and the lowest resolution, and read the job's cost before scaling up.

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: seedance25-test-001" \
  -d '{"model":"seedance-2.5","prompt":"A ceramic mug on a desk, slow push-in","resolution":"480p","duration":4,"aspect_ratio":"9:16","mode":"async"}'

Test budgets

The following figures use the same list prices as the tables above.

• Ten 4-second 480p tests: Runway 10 x $0.80 = $8.00; Sume 10 x $1.0747 = $10.75.
• Ten 4-second 1080p tests: Runway 10 x $2.72 = $27.20; Sume 10 x $5.6862 = $56.86.
• Sume's catalog reserves each job rounded up to a whole cent, so a 4-second 480p job reserves $1.08 while it is running.
• Draft mode on Runway bills a preview at the 480p rate and a later 1080p enhance as a separate call, which has no equivalent in the Sume docs I read.