Kling v2.1 Master
kling-v2-1-masterKuaishou's premium Kling v2.1 Master. Generates 1080p 5s and 10s clips from text or an image with strong dynamics and prompt adherence. The top tier of the Kling 2.1 family.
- Price
- US$0.336/s
- Aspect ratios
- 16:9, 9:16, 1:1
- Duration
- 5 or 10 s
- Input โ output
- Text + Image โ Video
- Developer
- Kuaishou (Kling)
- Updated
- September 23, 2026
This is an older version of the model.
Newer version available: Kling v3
Playground
Try Kling v2.1 Master
Input & output
This run
US$1.68 ยท 168 credits
Billed: 5 s
For accounts without a purchase: runs above 2 credits need a top-up.
New here?
10 free credits (US$0.10) when you sign up with Google
Usable 24 hours after sign-up, up to 5 runs per day and at most 2 credits per run. Other sign-in methods start without credits.
Examples
Prompt
a woman walking in a park
Length: 0:05
Settings
- aspect_ratio
- 16:9
- duration
- 5
Prompt
an anime woman runs down a city street in the rain (in an illustrated 1990s anime style), she is wearing a long dress
Length: 0:05
Settings
- aspect_ratio
- 16:9
- duration
- 5
InputPrompt
a woman gestures to the words with both hands, she is pleased, behind her it is raining
Length: 0:05
Settings
- aspect_ratio
- 16:9
- duration
- 5
About Kling v2.1 Master
Kling v2.1 Master is a model by Kuaishou (Kling) in the Video generation category. On Railwail, Kling v2.1 Master costs US$0.336 per second of video. A default run of 5 seconds costs US$1.68. Supported aspect ratios: 16:9, 9:16 and 1:1. Possible lengths: 5 or 10 s. Newer version: Kling v3.
Pricing
| Per second | US$0.336 per second of video |
|---|---|
| Default run (5 s) | US$1.68 per run |
- 1 credit = US$0.01
Cost calculator
Price calculator
Total
US$168.00
16,800 credits
Per run
US$1.68 ยท 168 credits
billed as 5 s
Fixed price per run, known before the run starts.
API
curl https://railwail.com/api/v1/videos/generations \
-H "Authorization: Bearer $RAILWAIL_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "kling-v2-1-master",
"prompt": "A slow drone shot over a misty pine forest at sunrise"
}'
# Response: {"job_id": "...", "status": "queued", ...}
# Poll until status is completed, failed or cancelled:
curl https://railwail.com/api/v1/jobs/JOB_ID \
-H "Authorization: Bearer $RAILWAIL_API_KEY"import os
import time
import requests
API = "https://railwail.com/api/v1"
headers = {"Authorization": f"Bearer {os.environ['RAILWAIL_API_KEY']}"}
job = requests.post(
f"{API}/videos/generations",
headers=headers,
json={
"model": "kling-v2-1-master",
"prompt": "A slow drone shot over a misty pine forest at sunrise",
},
).json()
while True:
status = requests.get(f"{API}/jobs/{job['job_id']}", headers=headers).json()
if status["status"] in ("completed", "failed", "cancelled"):
break
time.sleep(5)
print(status["status"], status.get("output_url"))const API = "https://railwail.com/api/v1";
const headers = {
Authorization: `Bearer ${process.env.RAILWAIL_API_KEY}`,
"Content-Type": "application/json",
};
const job = await fetch(`${API}/videos/generations`, {
method: "POST",
headers,
body: JSON.stringify({
model: "kling-v2-1-master",
prompt: "A slow drone shot over a misty pine forest at sunrise"
}),
}).then((r) => r.json());
let status;
do {
await new Promise((r) => setTimeout(r, 5000));
status = await fetch(`${API}/jobs/${job.job_id}`, { headers }).then((r) => r.json());
} while (!["completed", "failed", "cancelled"].includes(status.status));
console.log(status.status, status.output_url);Videos run asynchronously: the first call returns a job_id; query /api/v1/jobs/JOB_ID until the status is completed.
Specifications
- Model ID
kling-v2-1-master- Developer
- Kuaishou (Kling)
- Category
- Video generation
- Input
- Text, Image
- Output
- Video
- Aspect ratios
- 16:9, 9:16, 1:1
- Duration
- 5 or 10 s
- Billing
- Fixed price, known before the run
- Lifecycle
- Legacy
- Catalog entry updated
- September 23, 2026
Input parameters
Inputs and settings from the model's input schema. The example in the API section shows which of them the API accepts.
promptrequiredWhat video to generate
Type: TextDefault: โAllowed values: up to 2,000 charactersseedOptional seed for reproducibility
Type: IntegerDefault: โAllowed values: โstart_imageOptional reference image for image-to-video
Type: TextDefault: โAllowed values: โaspect_ratioType: ChoiceDefault:16:9Allowed values: 16:9, 9:16 or 1:1duration_secType: ChoiceDefault:5Allowed values: 5 or 10
Tags
- replicate
- kuaishou
- kling
- text-to-video
- image-to-video
- flagship
Use cases
Frequently asked questions
What is Kling v2.1 Master?
Kling v2.1 Master is a model by Kuaishou (Kling) in the Video generation category. On Railwail you can call it with an API key through the Railwail API.
How much does Kling v2.1 Master cost on Railwail?
On Railwail, Kling v2.1 Master costs US$0.336 per second of video. A default run of 5 seconds costs US$1.68. The price is known before the run starts. Usage is paid from prepaid credits; 1 credit equals US$0.01.
Which settings does Kling v2.1 Master support?
According to its input schema, Kling v2.1 Master knows these parameters: prompt (up to 2,000 characters), seed, start_image, aspect_ratio (16:9, 9:16 or 1:1) and duration_sec (5 or 10).
How fast is Kling v2.1 Master?
There are not enough measured runs of Kling v2.1 Master on Railwail yet to state a run time. It depends on the input, the settings and the load at the provider.
Is Kling v2.1 Master better than Kling v3?
That depends on the task. Kling v2.1 Master (Kuaishou (Kling)) and Kling v3 (Kuaishou (Kling)) are both models in the Video generation category. The comparison page shows their prices and specifications side by side.
Compare Kling v2.1 Master and Kling v3Can Kling v2.1 Master use an image as input?
Yes. Send the image in the start_image parameter.
How do I use Kling v2.1 Master through the API?
Create a Railwail API key and send your request with the model ID kling-v2-1-master. Code examples for curl, Python and JavaScript are in the API section of this page.
Comparable models
All in this category- Google Veo 2Google DeepMind
Google's state-of-the-art video generation model. Simulates real-world physics with various visual styles.
- Google Veo 3 (Replicate)Google DeepMind
Google's Veo 3 served via Replicate. Text-to-video with native synchronized audio generation. High-fidelity motion and scene coherence in short clips.
- Google Veo 3.1Google DeepMind
Latest Veo with image-to-video and context-aware audio
Use Kling v2.1 Master via the API
One API key for every model on Railwail. Usage is charged from prepaid credits, 1 credit = US$0.01.