Black Forest Labs: FLUX.2 [klein] 4B
Black Forest Labs FLUX.2 [klein] 4B API pricing
FLUX.2 [klein] 4B costs $0.0056 per megapixel on Oxyy. That is the pay-as-you-go price after the current 60% discount (Launch Promo; standard price $0.014). It generates images from text prompts and can work from reference images. It is the lowest-priced Black Forest Labs image model on Oxyy; for every model and rate, see FLUX API pricing.
Providers
Where this model runs, and what each route costs. Requests are sent to a healthy provider automatically; if one errors, the gateway retries against another serving the same model.
| Provider | Price | Unit | Latency | Throughput |
|---|---|---|---|---|
| Black Forest Labs | $0.0056 | per megapixel | 8.74s | — |
Capabilities (4)
Pricing
What this model costs on Oxyy, pay as you go. "Charged" is the rate a request is billed at; the standard price is shown beside it for reference.
| Rate | Standard price | Charged | Unit |
|---|---|---|---|
| Per megapixel | $0.014 | $0.0056 | per megapixel |
Discount. Charged rates include the current "Launch Promo" discount of 60% on every rate.
Specifications
- Model ID
flux-2-klein-4b- Developer
- Black Forest Labs
- Type
- Image generation
- Input
- Text and images
- Output
- Images
- Released
- Jan 15, 2026
- Series
- FLUX.2
- Image input
- Up to 20 MB each
- Endpoint
/v1/images/generations
Quickstart
Call flux-2-klein-4b with a POST to /v1/images/generations on https://api.oxyy.ai, using your Oxyy API key from the OXYY_API_KEY environment variable. The same key works for every model in the catalog.
import os
from openai import OpenAI
client = OpenAI(
base_url="https://api.oxyy.ai/v1",
api_key=os.environ["OXYY_API_KEY"],
)
response = client.images.generate(
model="flux-2-klein-4b",
prompt="A lighthouse on a cliff at sunset, watercolor",
n=1,
size="1024x1024",
)
print(response.data[0].url)Availability
The share of requests to this model that completed successfully over the last 30 days. Requests the caller cancelled, and requests still in flight, are not counted. When an upstream provider errors, the gateway retries against another provider serving the same model, so a single provider incident does not necessarily show up here.
Days are UTC days. Days with no completed requests are omitted rather than drawn at 100% — no traffic is not evidence of availability.
Activity
Token volume and request traffic to this model over time. Daily totals, UTC.
Prompt tokens measure input size. Completion tokens reflect total output length. Reasoning is not priced separately for this model, so it is not itemised here.
Frequently asked questions
What is FLUX.2 [klein] 4B?
How much does FLUX.2 [klein] 4B cost?
What can I send to FLUX.2 [klein] 4B?
Which API endpoint does FLUX.2 [klein] 4B use?
When was FLUX.2 [klein] 4B released?
What other models does Black Forest Labs have?
Alternatives to FLUX.2 [klein] 4B
Models of the same kind from other vendors, closest in price first. Prices are pay-as-you-go on Oxyy, through the same API key.