Runway Act Two overview
Runway Act Two by Runway ML
It supports minimal video generation with efficient resource usage, making it accessible for both developers and content creators.
Runway Act Two specs
- Model ID
runway/act_two- Developer
- Runway ML
- Input
- Text, Image, Video
- Output
- Video
- Endpoint
POST https://api.aimlapi.com/v2/video/generations
RunwayML Act Two is an advanced video generation API that animates characters using driving performance videos combined with character references. It enables efficient creation of high-quality short videos with a transparent, credit-based pricing system, making it accessible for developers and creators in creative and production workflows.
Performance Benchmarks
- Optimized for rapid generation
- Suitable for lightweight video synthesis tasks with efficient compute usage
Key Capabilities
- Supports variable-length video outputs with cost efficiency
- Easy integration for developers aiming to add video synthesis functionality
- Resource-efficient, making it suitable for applications with limited hardware or budget constraints
Comparison with Other Models
Vs. Pika Labs: Act Two's minimal 3-second video unit and transparent credit pricing make it better suited for rapid, budget-conscious prototyping, whereas Pika Labs may offer more customization for advanced workflows but at a higher price and computational requirement.
Vs. Kaiber: While Kaiber is recognized for its broader video transformation and style transfer capabilities, Act Two stands out by offering high-quality animated short videos with minimal compute needs, ideal for developers seeking straightforward deployment and predictable costs.
Vs. Sora: While Sora excels in delivering premium visual effects and extended scene generation, RunwayML Act Two stands out by providing immediate, cost-effective results for short-form animated videos, ideal for developers and content creators who value speed and affordability over advanced cinematic capabilities.
Limitations
- Minimum video length of 3 seconds may not suit applications requiring ultra-short clips or single-frame outputs
- Primarily optimized for short video generation; longer or complex videos may require more specialized solutions
Use cases
- Quick video content creation for social media and marketing
- Lightweight creative tools requiring video synthesis
- Prototyping and small-scale video generation projects
- Cost-conscious deployments needing short video outputs with predictable pricing
Runway Act Two API pricing
| Usage | Price | Unit |
|---|---|---|
| Video generation | $0.05 | per second |
Prices from the AI/ML API price list, checked on Nov 4, 2026.
Runway Act Two vs other video models: prices
AI/ML API rates for 5 models, per second.
| Model | Per second |
|---|---|
 Runway Act Two | $0.05 |
| Gen 4 Turbo | $0.05 |
 Wan 3.0 Video | $0.05 |
 Grok Imagine Video | $0.05 |
| Aleph | $0.195 |
How to use the Runway Act Two API
View docs
Build with your agent
Give your agent the model details, code and documentation.
1Get your API key
Create API keyexport AIMLAPI_KEY="8f2b4c7d9a1e6b3f…"2Make your first request
curl 'https://api.aimlapi.com/v2/video/generations' \
-H "Authorization: Bearer $AIMLAPI_KEY" \
-H 'Content-Type: application/json' \
-d '{
"model": "runway/act_two",
"character": null,
"reference": null
}'import os
import requests
headers = {
"Authorization": f"Bearer {os.environ['AIMLAPI_KEY']}",
"Content-Type": "application/json",
}
payload = {
"model": "runway/act_two",
"character": null,
"reference": null
}
response = requests.post("https://api.aimlapi.com/v2/video/generations", headers=headers, json=payload, timeout=120)
response.raise_for_status()
print(response.json())const response = await fetch("https://api.aimlapi.com/v2/video/generations", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
"model": "runway/act_two",
"character": null,
"reference": null
}),
});
if (!response.ok) throw new Error(`HTTP ${response.status}`);
console.log(await response.json());The request returns a generation id. Poll GET https://api.aimlapi.com/v2/video/generations?generation_id=<id> until the status is completed.
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Runway Act Two FAQ
What inputs and outputs does Runway Act Two support?
Runway Act Two takes image, text, video as input and returns video.
When was Runway Act Two released?
Runway Act Two became available on December 4, 2025.
How much does Runway Act Two cost?
Runway Act Two costs $0.05 per second on AI/ML API, billed as you go with no subscription.
How is Runway Act Two billed?
Runway Act Two costs $0.05 per second on AI/ML API, billed as you go with no subscription.
Can Runway Act Two take an existing image as input?
Yes, Runway Act Two accepts image input as well as a text prompt.
Who created Runway Act Two?
Runway Act Two was built by Runway.
How do I call Runway Act Two on AI/ML API?
Send a request to v2/generate/video/runway/generation with runway/act_two as the model id.
Is Runway Act Two available through a single API key?
Yes. Runway Act Two is served through AI/ML API, so the same key and endpoint format used for other models applies.
What does Runway Act Two actually do?
It generates expressive, full-body performance videos by transferring the motion from a driving video onto a subject.
What is the Runway Act Two model ID?
Use runway/act_two as the model parameter. Requests go to https://api.aimlapi.com/v2/video/generations with your AI/ML API key.