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Fastflux-2-klein-4b

FLUX.2 Klein 4B

Smallest FLUX.2 — very fast with solid quality. Great daily driver for paid plans.

Best for: Everyday generation, banners, social media, general content. Excellent speed-to-quality ratio.

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Quality steps
25
Fast preset
15
Max steps
50
Negative prompt
Yes
cURL
POST a single request to generate an image with FLUX.2 Klein 4B.
curl -X POST https://imageapi.org/api/v1/generate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "a cinematic mountain landscape at sunrise",
    "model": "flux-2-klein-4b",
    "width": 1024,
    "height": 1024,
    "num_inference_steps": 25
  }'
Python
import requests

resp = requests.post(
    "https://imageapi.org/api/v1/generate",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    json={
        "prompt": "a cinematic mountain landscape at sunrise",
        "model": "flux-2-klein-4b",
        "width": 1024,
        "height": 1024,
        "num_inference_steps": 25,
    },
    timeout=120,
)
print(resp.json())
Node.js
const res = await fetch("https://imageapi.org/api/v1/generate", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    prompt: "a cinematic mountain landscape at sunrise",
    model: "flux-2-klein-4b",
    width: 1024,
    height: 1024,
    num_inference_steps: 25,
  }),
});
console.log(await res.json());
Plan availability
FLUX.2 Klein 4B is included on the following plans.
  • basic
  • pro
  • enterprise

Frequently asked questions

How do I call the FLUX.2 Klein 4B model?
Send a POST request to https://imageapi.org/api/v1/generate with the body { "prompt": "...", "model": "flux-2-klein-4b" } and an Authorization: Bearer YOUR_API_KEY header.
What is FLUX.2 Klein 4B best for?
Everyday generation, banners, social media, general content. Excellent speed-to-quality ratio.
Does FLUX.2 Klein 4B support negative prompts?
Yes — pass a negative_prompt field to steer FLUX.2 Klein 4B away from unwanted concepts.
What inference step counts work best for FLUX.2 Klein 4B?
Use ~25 steps for production quality and ~15 steps when you want lower latency. The hard cap is 50 steps.
Which plans include FLUX.2 Klein 4B?
FLUX.2 Klein 4B is available on basic, pro, enterprise plans.

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