How much does one video cost?

It depends on the settings. The exact price is on the button before you start, and it updates with every change.

What if it doesn't work out?

If the run fails at the provider, no credits are charged. If the result is ready but you don't like it, press “Edit and retry”: the prompt and settings stay.

Which frame shapes are there?

3:5, 5:3. 9:16 suits Reels, Shorts and stories; 16:9 suits YouTube and websites.

5s, 10s. Pick the length in the settings before you start.

How is Runway Expand different from Runway Gen-4.5?

Both are in the Runway line-up. Switch between them in the line-up at the top of the page — the price of each is on its card.

Where are the results kept?

Every finished result goes to your Library. From there you can download it, publish it in the Community or use it as the base for the next one.

Runway Expand

Runway · Video · 5, 10s · 3:5, 5:3

API

Saved

Example

Your video will appear here

Fill in the settings and press Run. The result is also saved to your library.

Price

Reference price

No published price yet - this model is not in the public price list.

What the price depends on

This model is billed per second of output, so length is the biggest lever on the price.
Resolution and quality settings change the price. Change one and the number above follows.
A generation the provider fails is not charged. A chat answer is charged for what the model wrote and thought, even if you stop it.

Prices for every model Top up

Prices are in credits. What a credit costs is on the pricing page.

Which one to pick

Model	Key specs	Price from
Runway Gen-4.5	5, 10s · 16:9, 9:16, 4:3…	—
Runway Aleph 2	16:9, 4:3, 3:2…	—
Runway Gen-4	5, 10s	—
Runway Aleph	—	—
Runway Gen-4 Turbo	5, 10s	—
Runway Act-Two	—	—
Runway Expand· you are here	5, 10s · 3:5, 5:3	—

About the model

Runway Expand reframes a clip you supply to 3:5 or 5:3, filling in the new edges.

Produces: Video
Takes: text, video
Prompt: optional
Length: 5s, 10s
Frame shape: 3:5, 5:3

What you can set

Every setting of this model and the choices it allows — the same as in the form.

Driving videorequired
one file
Aspect ratio
3:55:3
Duration
5s10s

For developers

Run this from your own code

The same request the Generate tab sends, with the settings you have chosen.

Model id:runway-expand

curl -X POST https://seedara.ai/api/v1/generate \
  -H "Authorization: Bearer $SEEDARA_API_KEY" \
  -H "Content-Type: application/json" \
  --data '{
  "model": "runway-expand",
  "prompt": "Describe the shot: subject, action, camera move, lighting...",
  "params": {
    "aspect_ratio": "3:5",
    "duration_seconds": 5
  }
}'

This snippet updates as you change the form. Copy it once the settings are the ones you want.

Request parameters

What goes in `params`, by the names the API uses.

Required

The model refuses the request without these.

Parameter	Type	Accepted values	Default
`video_url` Driving video	video	—	—

Optional

Left out unless you set them - the provider then applies its own default.

Parameter	Type	Accepted values	Default
`aspect_ratio` Aspect ratio	one of a list	`3:55:3`	3:5
`duration` Duration	one of a list	`510`	5

How a generation runs

POST /v1/generate answers immediately with a job_id - it does not wait for the result.
Poll GET /v1/jobs/{id} until status is completed or failed.
A completed job carries output_url - the finished file.

curl https://seedara.ai/api/v1/jobs/JOB_ID \
  -H "Authorization: Bearer $SEEDARA_API_KEY"

Questions

Frequently asked about Runway Expand

New

Start now

Your first video —
in a minute

Describe what you want to see — the model does the rest.

Takes you to the settings — prompt, format and price are already there

No auto-charges
Pay only for a finished result
Works are kept in your Library

100credits as a gift

5–10sLength

3:5 · 5:3Frame shape