Runway Alternative: Comparing AI Video API Pricing

Key Takeaways

• Runway resells ByteDance's Seedance 2.0 as "Seedance 2.0 Pro," capped at 1080p. Siray's own Seedance 2.0 endpoint reaches native 4K — a resolution ceiling Runway's tier doesn't offer, though 4K is also the most expensive thing you can ask it for.
• Siray's Seedance 2.0 is not flat per-second: it bills on pixel volume, so the rate climbs with resolution — $0.084/s at 480p, $0.18/s at 720p, $0.45/s at 1080p, $0.93/s at 4K. The $0.084 figure on the price list is the 480p rate, not a blended one.
• Neither platform converts cleanly to the other: Runway meters by credit ($0.01/credit), which needs an assumed clip length to become a per-second number. This article compares resolution ceilings and billing structure, and declines to invent a per-second figure for Runway.
• Runway is a broader creative suite beyond just Seedance access; Siray is a direct API. If what you need is one model behind one key, that trade favors Siray — if you need Runway's wider toolset, it doesn't.

"Which API is cheaper" goes stale fast

Video-model pricing changes often enough that a number from a few months ago is a bad basis for a real decision — providers add tiers, cap resolution differently, or switch how they meter usage entirely. The numbers below were checked directly against Runway's own pricing page and, on the Siray side, against each model's billing table in the console on 2026-08-10.

That second detail matters more than it sounds, and an earlier draft of this article got it wrong. A public price list usually quotes a model's cheapest configuration — the rate you'd pay at its lowest resolution. If the model bills on pixel volume, that single figure describes one setting and nothing else, and reading it as a flat rate understates a 4K job by an order of magnitude. Per-model billing tables, not the summary list, are where the real rates live.

Video: Seedance 2.0, resolution and pricing model

Runway doesn't build its own video model here — it resells ByteDance's Seedance 2.0, branded "Seedance 2.0 Pro," metered at $0.01 per credit. Runway's own pricing page caps this tier at 1080p and doesn't separately document a lower, non-Pro resolution ceiling.

Siray offers Seedance 2.0 directly, in two tiers. The regular tier's size parameter goes up to 4k — Siray's own OpenAPI spec confirms 480p, 720p, 1080p, and 4k as valid values. The Fast tier trades that ceiling for speed: 480p or 720p only.

Both bill on pixel volume rather than a flat rate. Tokens come out as (output height × output width × (input duration + output duration) × 24) / 1024, charged per 1K tokens, which means resolution is a live term in the price. Passing a video in lowers the token rate — the one input that makes a call cheaper instead of dearer. The console's own conversion tables resolve to:

That resolution gap is the headline difference: if a project needs native 4K Seedance 2.0 output, Runway's Pro tier can't produce it at all, regardless of price. Worth stating plainly, though, that 4K is not a free upgrade — at $0.93/s it costs about 11× the 480p rate, so "Siray goes higher" and "Siray goes cheaper" are two different claims and only the first one is about 4K.

Where the comparison isn't apples-to-apples

Two honest caveats worth stating plainly. First, the pricing models don't convert cleanly: Runway's credits meter by output, not by wall-clock second, so turning $0.01/credit into an exact per-second figure would require assuming a specific clip length — that's not a number this article is going to fabricate. Since Siray's side varies by resolution and Runway's varies by an undisclosed credit-per-output rule, this article makes no claim about which platform is cheaper. What's comparable without guessing is the resolution ceiling and the fact that Siray's rate is knowable in advance once you fix the parameters.

Second, Runway is a full creative product — timeline editing, asset management, and a broader model catalog beyond Seedance access alone. Siray's offering here is a direct API endpoint, not a creative suite. If the actual need is Runway's wider toolset, this comparison doesn't cover that gap; if the need is programmatic access to Seedance 2.0 itself, that's exactly what's being compared.

One API key

The practical case for Siray isn't just the 4K ceiling — it's not having to route a video-generation feature through a product built primarily for a different workflow. One API key, a published formula you can compute a budget from before you call it, and a resolution tier that goes as high as the model itself supports.

For a similar breakdown against another provider, see Replicate Alternative: Comparing AI Media APIs on Price and Speed and Fal.ai Alternative: Comparing AI Video APIs on Price and Speed.

Create your free Siray account and check these numbers against your own workload — pricing pages change, so verify current rates before committing a production budget.