Runway Gen-4.5
Gen-4.5 is Runway own video model: clips of two to ten seconds, a 720p ceiling, and no audio. On Runway own price list it costs twelve credits per second, which at their stated credit price is twelve cents.
- two to ten seconds
- 720p ceiling
- no native audio
Last checked: This is a reference page. It is re-checked against the vendor sources and updated when a new version ships. What changed
Where these numbers came from
This is the only model in the table whose specification we took from the maker OpenAPI schema rather than from a product page. The duration parameter accepts two to ten seconds, and the list of permitted aspect ratios tops out at 1280:720, which is 720p. There is nothing to interpret: this is the same file the server validates requests against.
What is missing from the schema, and what that means
In that same file, veo3.1 has an audio parameter and so does seedance2_5, both defaulting to on. Gen-4.5 has no such parameter. No sound comes out of this model, and it has to be produced separately.
There is no references array either, where seedance2_5 in the same file takes up to thirty images, ten videos and ten audio clips. But a missing API parameter does not prove that Runway own interface refuses references, so we left this model reference cell marked unverified in the table, and it loses twenty points of weight for it. If Runway publishes the number anywhere, it goes in the same day and the rank moves up.
Price, which is genuinely comparable here
Runway price list sets a credit at one cent and then prices a second of video in credits. Gen-4.5 is twelve credits per second, so twelve cents. Seedance 2.5 at 720p is thirty credits, and Veo 3.1 with audio is forty. This is the only place where all three are priced side by side in one currency and one unit, and it is what keeps Gen-4.5 alive despite the thinner feature set: each second costs about a third of Veo.
Using it from Iran
We check this ourselves from an Iranian connection, because no vendor documents it and every listicle guesses.
- Reachable
- not checked
- Payment
- no working route
- Free tier
- no
- Measured on
How we checked: Runway publishes no country list, but its terms of use state that its products and services are subject to US export control laws and may not be exported or re-exported without prior US government authorisation. We read that on their own page rather than measuring a network.
What it is good at
- The cheapest second of video among the three models Runway prices side by side: twelve cents
- Its specification is read from the official API schema, so there is nothing to interpret
- It sits on the same API and the same dashboard as the competing models
Where it falls short
- No audio. The API schema carries no audio parameter for this model, so sound has to be added separately.
- The ceiling is 720p, which is not enough for a professional delivery.
- Ten seconds is the second shortest length in the table, after Veo.
- Runway publishes no reference-input ceiling, so that column stays unverified in our table and scores nothing.
- Runway terms of use place its services under US export control law.
Our take
If you are producing a high volume of short silent clips and cost is what binds you, this is the cheapest thing on the table. For anything else, look at its three empty columns and go back to the top of the ranking.
Questions people actually ask
Does Gen-4.5 generate audio
No. In Runway API schema this model has no audio parameter, while veo3.1 and seedance2_5 in the same file both do.
What does a second of Gen-4.5 video cost
Twelve credits per second, and Runway sells a credit for one cent. That is twelve cents per second of output.
Sources
- Runway API, available models vendor source 12 August 2026
- Runway API, OpenAPI schema vendor source 12 August 2026
- Runway API pricing, per second of output vendor source 12 August 2026
- Runway terms of use vendor source 12 August 2026