Every AI Video Engine: What Each One Accepts and Costs

There are now 28 engines in the WorkCrafter video tool, and the honest problem with a list that long is that engine names tell you nothing. This article is the comparison we wanted and could not find: what each one costs per second, how long a clip it will actually accept, and what shape that clip can be.

One thing to say up front about where these numbers come from. The clip lengths and aspect ratios were read from the providers' own APIs on November 10, 2026 — not from documentation, because the documentation does not publish them. Prices and prose, yes; accepted parameter values, no. That gap matters more than it sounds: send a plausible-looking length to an engine that does not take it and the request is refused after the credits have left your account. So we asked the API instead of guessing, and these are its answers.

The short version

• **Cheapest overall:** LTX Video 13B at 2 credits per second, and the two newer LTX engines at 3.
• **Cheapest premium:** Grok Imagine Lite at 3.6 credits per second.
• **Longest single shot:** Kling 4.0, up to 30 seconds in one generation.
• **Widest choice of shapes:** Kling 4.0, including a 2200×940 that is close to anamorphic 2.35:1.
• **Most expensive:** Veo 3.1 with generated sound at 48 credits per second; without sound, Seedance 2 and Seedance 2.5 at 36. There is roughly a tenfold spread across the premium range, so the engine you pick matters more to your bill than the length of your clip.

The standard engines

LTX Video 13B costs 2 credits per second and takes 2 or 4 seconds. LTX Video 2 and LTX Video 2.5 cost 3 and go up to 10. LTX Video 2.5 is the newest of the three and the one to try first. Hailuo H3 Turbo is the fourth standard engine, at 4 credits per second for 4 to 10 seconds. At this price you can afford to iterate, which is usually worth more than a better engine on the first attempt.

The low-cost premium engines

This band is where the November additions changed things most, because it barely existed before.

• **Grok Imagine Lite — 3.6 credits/second.** Up to 15 seconds. A 10-second clip costs 36 credits, about one second of Seedance 2. If you are producing volume, start here.
• **Gemini Omni Flash 1.2 — 8.4 credits/second.** Up to 15 seconds, with a floor of 8 credits per run. It has no square format at all: landscape and portrait only, so a square brief will come back as 16:9.
• **Hailuo H3 Max — 9.6 credits/second.** Up to 15 seconds. Unusual in one respect: it refuses an aspect-ratio instruction entirely and decides the shape itself.
• **Kling 3.0 Standard — 10.8 credits/second.** Up to 15 seconds, 720p. The cheapest way into the Kling family.
• **Kling 4.0 Flash — 11.3 credits/second**, up to 20 seconds, 720p only, with a 35-credit floor per run.
• **Veo 3.1 Fast — 12 credits/second**, or 18 with generated sound. 4, 6 or 8 seconds.
• **Gemini Omni, Omni Flash 1.1, Wan3 and Hailuo 3 — 12 credits/second.** Hailuo 3 goes to 15 seconds; it thinks in proportions rather than pixels, so you choose 16:9, 9:16 or 1:1.

The middle of the range

• **Gen-4.5 — 14.4 credits/second.** 5, 8 or 10 seconds.
• **Kling 3.0 Pro — 14.4 credits/second.** Up to 15 seconds at 1080p. The best value in the family if you need 1080p rather than length.
• **Kling 2.5 Turbo Pro — 14.4 credits/second.** Accepts 5 or 10 seconds and nothing else.
• **Kling O3 Standard — 15.6 credits/second.** 5 or 10 seconds, 720p.
• **Wan3 Prime — 16.8 credits/second.** 5 or 10 seconds.
• **HappyHorse 1.0 — 18 credits/second.** Up to 15 seconds, with ten output shapes, which is a lot of flexibility at this price.
• **Seedance 2 Mini — 18 credits/second**, with a 34-credit floor per run.
• **Kling 4.0 — 18.9 credits/second.** The only engine that does 30 seconds in one pass.
• **Grok Imagine 1.5 — 19.2 credits/second.** Up to 15 seconds.
• **Kling O3 Pro — 20.4 credits/second.** 5 or 10 seconds, 1080p.

The top of the range

• **Veo 3.1 — 24 credits/second**, or 48 with sound. 4, 6 or 8 seconds. Sound doubles the price here, so leave it off unless you want it.
• **Seedance 2 Fast — 28.8 credits/second**, with a 53-credit floor per run.
• **Seedance 2.5 — 36 credits/second**, with a 96-credit floor per run.
• **Seedance 2 — 36 credits/second**, with a 68-credit floor per run.

Which one should you actually use?

Pick by the constraint that is real for your job, not by the engine that sounds most impressive.

1. **You are still finding out whether the idea works.** LTX Video 2.5 at 3 credits a second, or Grok Imagine Lite at 3.6. Spend the savings on more attempts — on a first try, the prompt is almost always the problem, not the engine.
2. **You need a long unbroken shot.** Kling 4.0, and only Kling 4.0, gives you 30 seconds in one pass. Everything else tops out at 15 or 20.
3. **You are cutting the result anyway.** Then length is not a feature you need. Generate several short clips on a cheap engine and join them in the free browser editor, which costs nothing.
4. **You need 1080p.** Kling 3.0 Pro at 14.4 credits a second is the cheapest route to it.
5. **You need a specific shape.** Check the engine takes it before you commit. Gemini Omni Flash 1.2 has no square; Hailuo H3 Max picks for itself; Kling 4.0 has the widest set including near-anamorphic.
6. **You want generated sound.** Veo 3.1 and Veo 3.1 Fast generate it, and in both cases it costs roughly double. A separate voice-over over a silent clip is usually cheaper and easier to fix.

Watch the minimum charges

Four engines bill a floor per run regardless of clip length: Kling 4.0 Flash, Seedance 2 Mini, Seedance 2.5 and Gemini Omni Flash 1.2. On those, a 2-second test costs the same as a longer clip, so short experiments are wasted money. Either test on an engine without a floor, or make the test long enough to be worth the floor you are paying anyway.

Why this list is shorter than it was last week, or longer

Engine catalogues move. Providers add models, rename them, and withdraw them without notice — an engine we offered in October was quietly replaced by its own Turbo variant, and picking it had been running something else. The menu is now checked against the providers continuously, so an engine that is withdrawn disappears from it on its own rather than waiting for someone to notice. If an engine named here is not in your menu, that is why, and the prices in this article may have moved with it. The tool always shows the current price before you run anything.

Related reading

• Kling 4.0 Has Shipped: Real Limits, Real Prices
• The AI Video Tool: Picking the Right Engine
• How Much Does AI Generation Cost?
• Free AI Video Generator: Turn Text into Video in Minutes
• Open the video generator

Sources

• **Accepted clip lengths and aspect ratios:** read from the Runway API on 2026-11-10 by submitting a deliberately invalid request and reading the accepted values out of the rejection. We could not find these published in prose by any provider.
• **Prices:** the WorkCrafter price table as of 2026-11-10. The tool shows the live price before each run, which is the figure that governs.
• Runway models guide and pricing guide — read 2026-11-10, for which engines exist and which bill a minimum per run.