Grok Imagine video cost: a 15-second clip is $1.20 at xAI's 1.5 rate

xAI's video guide says that "both duration and resolution affect the total cost," and that a video can run up to 15 seconds. At the listed rate for grok-imagine-video-1.5, $0.080 per second, a 15 second clip costs 15 x $0.080 = $1.20. The older grok-imagine-video at $0.050 per second costs $0.75 for the same length.

Cost by length at the listed rates

Rates are from the xAI models page. The table is my arithmetic, and it assumes the listed rate applies to every length.

What is not on the page

The xAI pages I read show one per-second figure for each model. They do not show a rate for each resolution, though the guide says resolution affects cost. I cannot tell you the resolution split from those pages. To plan a budget, do not assume the listed rate covers every resolution: run one short test at your target resolution, and read the charge before you queue a long run.

Planning the same clip on Sume

Sume's grok-imagine-video-1.5 takes 4 to 15 seconds at 480p and 720p, image-to-video only. The Sume docs say to use GET /v1/videos/models for model prices, and I do not state a Sume per-second figure for this model. The billing rules for any Sume video job are the same:

• Sume reserves the amount at submit. If your balance is below the reserve, the call returns 402 insufficient_credits.
• The reserve is the provider list times 1.25, and the Sume docs say the billable amount is what usage.cost shows on the poll.
• Send an Idempotency-Key so a retry does not create a second job and a second reserve.

A simple budget method

Budget a 15 second clip first, then cut it. If a 15 second clip at your resolution is out of budget, a 4 second clip is the Sume minimum for this model, so you can scale down in steps. A good test is to start with 4 seconds at 480p, read usage.cost, and scale from that number.