What is Credit-based billing? Definition, key points and related tools
How most AI video platforms bill: buy credits, deduct per call. Compare on cost per finished second or per series, and check expiry (Runway's Standard and Pro credits reset monthly while Max rolls over up to one month; invideo credits don't roll over; Vidu subscription credits last 30 days).
Two exchange rates inside every credit price
A credit price hides two conversions. The first turns money into credits: pack price or monthly fee divided by the credits it buys, which moves with plan size, annual billing and how much of the allowance you actually spend. The second turns credits into output: model × resolution × duration × options such as audio. The comparable number is the product of the two, dollars per finished second; a credit count on its own says nothing across platforms. The credits, tokens and per-second explainer runs one clip through several vendors.
Runway shows how far the first rate moves inside one vendor. Gen-4.5 costs 60 credits per 5 seconds, 12 per second. On Standard, $15 a month buys 625 credits ($0.024 each), so a second costs about $0.29; on Max billed annually, $76 a month buys 9,500 ($0.008 each), about $0.10 per second (Runway pricing). Same model, same clip, a 3× gap. On SceneMixer the default video tier (Wan 3.0 · 480P) is 10 credits per second; at its published credit prices ($0.006 per credit via the largest pack or an annual membership, $0.015 in the smallest pack) that is $0.06–$0.15 per second, a 2.4× spread from the purchase route alone (SceneMixer pricing).
Drama platforms also bill steps other than video in credits — SceneMixer, for instance, prices parsing per 1,000 characters and storyboards per episode — so compare per episode or per series, not per clip. The cost breakdown guide lists the line items.
What to check before you buy
| Vendor | Plan credits | Purchased credits | Failed or blocked generations |
|---|---|---|---|
| Runway | Standard and Pro reset within 24 h of the billing date; Max rolls over up to one month | Extra purchases from 1,000 credits | Developer API: moderated generations cost the same credits as successful ones; no refund for input-moderation (SAFETY.INPUT) failures (moderation, task failures) |
| Kling | Valid 1 month | Valid 2 years; shorter-validity credits are spent first | Refunded when a generation fails (credit policy) |
| Vidu | Valid 30 days | Valid 2 years (bonus credits too) | Not stated on the pricing page (Vidu) |
| invideo AI | Unused credits do not roll over | Not disclosed | Not disclosed (invideo) |
| Luma Dream Machine | Not stated on the pricing page | Not stated | Not stated (Luma) |
| SceneMixer | Membership credits join the balance and spend like purchased credits (pricing); credits without a stated expiry do not expire | Same rule | Failed, moderation-blocked or timed-out tasks refunded automatically (terms) |
Two more checks the table cannot show. Utilization: a subscription credit is worth fee ÷ credits when you spend all of them; at half usage its price doubles. Options priced separately: Vidu's API adds 15 credits per task when audio is switched on for image- or reference-to-video (Vidu API pricing), and resolution tiers change the credits per second on every platform.
Common mistakes and their causes
- Comparing credit counts across tools. "60 credits a clip" on one platform and "10 credits a clip" on another use different exchange rates; convert both to dollars per second first.
- Buying annual for a short project. An annual plan still hands out its credits month by month, and allowances that reset or expire after 30 days to a month are lost in every month production pauses between seasons.
- Budgeting one attempt per segment. Every retake is paid again; budget credits per kept segment, not per planned segment.
- Ignoring the refund rule. A genre that trips filters costs more on a platform that charges for blocked output; see content moderation.
- Reading the free allowance as a sample of the paid product. Free tiers often differ in resolution, watermark or commercial rights, so the output you evaluate may not be the output you would ship.
Comparing plans in four steps
- Price one credit on the plan you would actually buy, at the share of the allowance you would actually use.
- Read the credits per second for your model, resolution and options (audio, reference inputs).
- Multiply by your attempts per kept segment, then add the non-video steps of the pipeline.
- Compare the total per episode, and check expiry against your production calendar.
Cross-tool starting prices and free allowances are on the pricing comparison.
Key figures and sources
| Figure | Value | Source | Date |
|---|---|---|---|
| Runway plans and Gen-4.5 | Standard $15/mo ($12 annual) 625 credits; Max $95 ($76 annual) 9,500; Gen-4.5 60 credits per 5 s; Standard/Pro credits reset each cycle | runway.com | 2026-09-12 |
| Kling credit validity | Subscription credits 1 month; purchased credits 2 years; failed generations refunded | kling.ai | 2026-09-12 |
| Vidu credit validity | Subscription credits 30 days; purchased and bonus credits 2 years | www.vidu.com | 2026-09-12 |
| invideo AI credits | Plus $50 per seat/mo billed annually for 2,000 credits; unused credits do not roll over | invideo.io | 2026-09-12 |
| SceneMixer credits | No expiry unless stated at purchase; failed, moderated or timed-out tasks refunded automatically | scenemixer.com | 2026-09-12 |
FAQ
Do unused credits roll over?
Mostly not for plan credits. Runway Standard and Pro reset each cycle while Max carries up to one month; Kling subscription credits last one month and purchased credits two years; Vidu subscription credits last 30 days and purchased credits two years; invideo AI does not roll unused credits over. SceneMixer's terms say credits without a stated expiry do not expire.
Are credits refunded when a generation fails or is blocked?
It depends on the vendor. Kling's credit policy refunds failed generations; SceneMixer's terms refund failed, moderation-blocked and timed-out tasks; Runway's developer API charges moderated generations the same as successful ones; Google does not charge for Veo videos blocked from generating. Where a pricing page is silent, check the help center before budgeting.
Does a bigger pack lower the cost per second?
It lowers the price per credit, not the credits a second costs. On Runway a credit is $0.024 on Standard billed monthly and $0.008 on Max billed annually, while Gen-4.5 stays at 12 credits per second. On SceneMixer the smallest pack is $1.49 for 100 credits ($0.015 each) and the largest pack or an annual membership brings a credit down to $0.006. The saving holds when the credits are spent before they expire and the plan fits your monthly volume.
Sources
- https://runway.com/pricing
- https://docs.dev.runwayml.com/api-details/moderation/
- https://docs.dev.runwayml.com/errors/task-failures/
- https://kling.ai/docs/point-policy
- https://www.vidu.com/pricing
- https://platform.vidu.com/docs/pricing
- https://invideo.io/pricing/
- https://lumalabs.ai/pricing
- https://scenemixer.com/terms/
- https://scenemixer.com/pricing/
- https://ai.google.dev/gemini-api/docs/pricing