AI video API billing units: per clip, per second, credits or tokens

Seven video APIs this week use seven different billing units, so their price pages cannot be compared until you convert them to dollars for one clip. Luma bills per generation, LTX and MiniMax per second, Runway in credits worth one cent, Vidu in credits worth 0.03125 RMB, Google in tokens, and Sume in a USD wallet balance with a reservation at submit.

Converting to one clip

Pick a clip, then convert each row. For a 5-second 720p clip: Luma $0.30, LTX Fast 5 x $0.09 = $0.45, Runway 5 x 12 credits = 60 credits = $0.60, Google Omni 5 x 5,792 = 28,960 tokens x $17.50 / 1,000,000 = $0.5068, MiniMax 5 x $0.08 = $0.40. Vidu's 720p row is 19 credits per second in our reading of its table, so 95 credits, or 2.97 RMB (95 x 0.03125); convert RMB to dollars at your own rate because Vidu's page does not do it.

What changes in your code

Per-second and per-generation units can be estimated before you send a request. Token billing needs a token estimate, and credit billing needs a conversion constant that vendors can change. Sume's docs say the estimated price is reserved at submit, captured on success and released or refunded on failure, so your client can compare the reserve with the final charge. Use the Idempotency-Key header on submits that you may retry, so a retry returns the original job instead of a second billable one.

• Store the unit with every price you log.
• Convert to USD per output second for comparison only after you have confirmed the clip length and resolution.
• Re-read the vendor page before each budget, since the figures are as of 2026-10-09.

A small converter

Keep one helper that turns each vendor's rate card into dollars per output second at a stated resolution, and store the date you read the page. Vendors change prices without notice, and the Sume docs say that GET /v1/videos/models is the live source for capabilities and pricing SKUs. A spreadsheet row per vendor with unit, rate, date and URL is enough to keep a budget honest.