Cheapest AI Video API 2026: Per-Second Costs Ranked

If you are adding AI video to a product, the per-second price is the first number you check and the last one you should trust. This guide ranks the verified rates, then shows the three factors that decide your actual bill: resolution, retries, and quality per dollar. All prices were checked against vendor and host pages on May 26, 2026.

1. Per-second prices, ranked

Model (route)	Per-second cost	Notes
Runway Gen-4 Turbo (direct API)	$0.05/s[1]	5 credits/s @ $0.01/credit
Kling 2.5 Turbo Pro (fal.ai)	~$0.07/s[2]	$0.35 base 5s + $0.07/extra s
Wan 2.1 i2v 480p (Replicate)	$0.09/s[4]	Open-weight; 720p is $0.25/s
Luma Ray 2 (fal.ai)	~$0.10/s[3]	540p base; 720p 2x, 1080p 4x
Runway Gen-4.5 (direct API)	$0.12/s[1]	12 credits/s; higher quality

Runway Gen-4 Turbo sits at the bottom of the credible range at $0.05 per second^[1]. Open-weight Wan 2.1 on Replicate is cheap at 480p ($0.09/s) but jumps to $0.25/s at 720p^[4]. Kling and Luma sit in between on fal.ai^[2][3]. Pika is absent because it has no self-serve API to price^[5].

2. Why the cheapest sticker is not the cheapest API

The lowest per-second rate often costs the most in practice. A cheap model that needs three attempts to produce a usable clip, or that only looks acceptable at a higher resolution tier, ends up pricier per finished clip than a slightly more expensive model that delivers on the first try at lower resolution. The right metric is cost per accepted clip, which folds in quality, retries, and the resolution you actually ship.

3. Resolution multiplies the bill

Resolution is the most common hidden multiplier. Luma Ray 2 lists a 540p base rate, with 720p costing 2x and 1080p costing 4x^[3], so a clip you priced at $0.10 per second is really $0.40 per second once you ship 1080p. Wan 2.1 shows the same pattern on Replicate: $0.09/s at 480p but $0.25/s at 720p^[4]. Always price the resolution you will publish, not the base tier in the headline.

4. Budget for retries, not single takes

Video generation is probabilistic, so you rarely accept the first output. If you keep one clip in three, your effective cost is three times the per-clip rate. A 5-second Runway Gen-4 Turbo clip is about $0.25 per generation, so at a one-in-three acceptance rate the cost per shipped clip is closer to $0.75^[1]. Track your acceptance rate per model and use it to compute the real number; a model with a higher acceptance rate can beat a cheaper one that you reroll constantly.

5. A method to find your cheapest option

1. List your hard requirements: resolution, length, and minimum quality bar.
2. Run the same prompts through two or three models on an aggregator like fal.ai or Replicate.
3. Record acceptance rate per model, not just the per-second price.
4. Compute cost per accepted clip = per-clip cost ÷ acceptance rate, at the resolution you ship.
5. Pick the lowest cost per accepted clip that clears your quality bar, then revisit direct API access if monthly volume is high.

To turn that per-clip number into a monthly budget for your expected volume, use the AI stack cost calculator, and the ROI payback calculator to check the video feature earns back its generation cost. For the model-by-model comparison with access caveats, see Runway vs Kling vs Pika vs Luma.

All pricing figures verified against official pricing and host pages as of 2026-05-26.

Frequently asked questions

What is the cheapest AI video API in 2026?

By headline per-second rate, Runway Gen-4 Turbo is among the cheapest credible options at $0.05 per second, verified against Runway's API pricing in May 2026. Open-weight models hosted on aggregators are competitive too: Wan 2.1 image-to-video runs $0.09 per second at 480p on Replicate. Kling 2.5 Turbo Pro on fal.ai is about $0.07 per second and Luma Ray 2 about $0.10 per second at base resolution. The true cheapest depends on the resolution and quality you need; a low 480p rate is not comparable to a 1080p clip from a higher-end model.

Is a cheaper per-second rate always cheaper overall?

No. Three things change the real bill. First, resolution: some models multiply the base rate for 720p and 1080p, so Luma Ray 2 at $0.10 per second base becomes roughly $0.40 per second at 1080p. Second, retries: video generation often needs several attempts to get a usable take, so multiply the per-clip cost by your real acceptance rate. Third, quality: a cheaper model that needs more retries or higher resolution to look right can cost more per finished clip than a pricier model that nails it first time. Compare cost per accepted clip, not the sticker per second.

Can I get a cheap video API from Pika?

Not via a self-serve API. As of May 2026, Pika sells consumer subscriptions from around $8 per month, but it does not publish a self-serve developer API; programmatic access is a partner arrangement or runs through a third-party host like fal.ai. For a budget API you can sign up for today, look at Runway's direct API, open-weight models like Wan on Replicate, or Kling and Luma through fal.ai, rather than Pika's direct offering.

Should I use a model aggregator to keep video costs low?

Often yes. Aggregators like fal.ai and Replicate expose many video models behind one API key with published per-second prices, which lets you A/B test models for quality per dollar without separate contracts, and switch to a cheaper model when one is good enough. The tradeoff is a small platform margin and dependence on the aggregator's uptime and rate limits. Going direct, like Runway's own API, can be cheaper at high volume and gives you the official SLA. Start on an aggregator to find the cheapest model that meets your quality bar, then revisit direct access if volume grows.