Runway Gen-4.5
Gen-4.5 is Runway internal video model: clip length ranges from two to ten seconds, with a 720p resolution ceiling and no audio channel. Per Runway pricing list, the rate is twelve credits per second, equal to twelve cents at the stated per-credit rate.
- two-to-ten-second production range
- 720p resolution ceiling
- no native audio channel
Last checked: This is a reference page. It is re-checked against the vendor sources and updated when a new version ships. Change log
Source of the technical specification
This is the only model in the table whose specification is drawn directly from the vendor OpenAPI schema rather than a product page. The duration parameter accepts a range of two to ten seconds, and the list of permitted aspect ratios caps at 1280:720, equivalent to 720p. These values are not open to interpretation: they are the same file the server uses to validate input.
Missing parameters in the schema, and their implication
In the same schema file, the veo3.1 model carries an audio parameter, as does seedance2_5, both defaulting to on. Gen-4.5 has no such parameter. This model produces no audio output; it has to be generated in a separate process.
A references array is likewise absent from this model schema, whereas seedance2_5 in the same file accepts up to thirty images, ten videos and ten audio files as reference input. However, the absence of a parameter in the API does not establish that Runway own interface withholds reference-input support; for that reason this model reference-input cell is recorded as unverified in our table, costing it twenty points of criteria weight. If Runway publishes this specification, it is added to the table the same day and the rank is adjusted.
Pricing, the one directly comparable metric
Runway pricing list sets the credit rate at one cent and expresses the cost per second of video in credits. Gen-4.5 consumes twelve credits per second, equal to twelve cents. Seedance 2.5 at 720p consumes thirty credits, and Veo 3.1 with an audio channel consumes forty. This is the only point at which all three models are priced side by side in a single currency and unit, and it is what keeps Gen-4.5 in circulation despite its lower capability tier: its per-second cost runs at roughly one third of Veo.
Specifications
Every number here comes from the vendor's own page, with that page linked beside it.
Using it from Iran
This column carries a date and says how it was checked, because most listicles guess it. Where we have only read a vendor policy page, the note below says exactly that.
- 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 specify that its products and services are subject to United States export control law and may not be exported or re-exported without prior US government authorisation. This specification was drawn from the vendor own documentation rather than a network measurement.
Documented strengths
- The lowest per-second rate among the three models Runway prices side by side: twelve cents
- The technical specification is drawn from the official API schema, with no interpretive ambiguity
- It is deployed on the same API infrastructure and dashboard as the competing models
Known weaknesses and limits
- No audio channel. The API schema defines no audio parameter for this model, so audio must be produced in a separate process.
- The resolution ceiling is 720p, insufficient for a professional delivery pipeline.
- A ten-second clip length is the second-shortest value in the table, after Veo.
- Runway has not published a reference-input ceiling, so this column remains unverified in our table and scores nothing.
- Runway terms of use place its services under United States export control law.
Technical verdict
For high-volume production of short, audio-free clips under a cost constraint, this is the lowest-cost option on the table. For any other use case, its three empty columns should be weighed against the higher-ranked options.
Frequently raised questions, with documented answers
Does Gen-4.5 generate audio output
No. In Runway API schema, this model has no audio parameter, while veo3.1 and seedance2_5 in the same file both carry one.
What does a second of Gen-4.5 video cost
Twelve credits per second, and Runway sells a credit for one cent. That equals twelve cents per second of output.