Black Forest Labs' distilled 9 billion parameter image generation model with sub-second inference and multi-reference support
flux.2-klein-9b
Starting from
Prices shown are in USD · Some prices estimated from per-megapixel or per-token pricing
See all providersFastest generation through fal at 2,701ms median latency with 100.0% success rate.
Aggregated from real API requests over the last 30 days.
| # | Provider | p50 Gen Time | p95 Gen Time | Success Rate | TTFB (p50) |
|---|---|---|---|---|---|
| 1 | fal | 2,701ms | 29,003ms | 100.0% | 2,197ms |
FLUX.2 [klein] 9B is available from 3 providers, with per-image pricing starting at $0.006 through fal.ai.
fal/flux.2-klein-9b
fal/flux.2-klein-9b-edit
replicate/flux.2-klein-9b
https://api.lumenfall.ai/openai/v1
flux.2-klein-9b
curl -X POST \ https://api.lumenfall.ai/openai/v1/images/generations \ -H "Authorization: Bearer $LUMENFALL_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "flux.2-klein-9b", "prompt": "", "size": "1024x1024" }'# Response:# { "created": 1234567890, "data": [{ "url": "https://...", "revised_prompt": "..." }] }import OpenAI from 'openai';const client = new OpenAI({ apiKey: 'YOUR_API_KEY', baseURL: 'https://api.lumenfall.ai/openai/v1'});const response = await client.images.generate({ model: 'flux.2-klein-9b', prompt: '', size: '1024x1024'});// { created: 1234567890, data: [{ url: "https://...", revised_prompt: "..." }] }console.log(response.data[0].url);from openai import OpenAIclient = OpenAI( api_key="YOUR_API_KEY", base_url="https://api.lumenfall.ai/openai/v1")response = client.images.generate( model="flux.2-klein-9b", prompt="", size="1024x1024")# { created: 1234567890, data: [{ url: "https://...", revised_prompt: "..." }] }print(response.data[0].url)How we handle parameters across different providers
Not every provider speaks the same language. When you send a parameter, we handle it in one of four ways depending on what the model supports:
| Behavior | What happens | Example |
|---|---|---|
passthrough |
Sent as-is to the provider | style, quality |
renamed |
Same value, mapped to the field name the provider expects | prompt |
converted |
Transformed to the provider's native format | size |
emulated |
Works even if the provider has no concept of it | n, response_format |
Parameters we don't recognize pass straight through to the upstream API, so provider-specific options still work.
FLUX.2 [klein] 9B is ranked #17 in Image Editing with an Elo of 1132 and #27 in Text-to-Image with an Elo of 1212 on the Lumenfall Arena, where real users pick the better image in blind comparisons. These rankings are based on 2 blind-vote competitions.
“Ad for 'Magic Burger'. Dynamic, exploded burger with all components (bun, patty, cheese, lettuce, tomato, sauce) suspended in mid-air. Emphasize photorealistic detail and a sense of motion. Dark, fiery background with glowing embers. Integrate text: 'MAGIC BURGER' as a prominent title, 'LIMITED TIME ONLY' as a secondary message, and '€6.99' in a starburst, all rendered with a fiery, glowing effect.”
“Ad for 'Magic Burger'. Dynamic, exploded burger with all components (bun, patty, cheese, lettuce, tomato, sauce) suspended in mid-air. Emphasize photorealistic detail and a sense of motion. Dark, fiery background with glowing embers. Integrate text: 'MAGIC BURGER' as a prominent title, 'LIMITED TIME ONLY' as a secondary message, and '€6.99' in a starburst, all rendered with a fiery, glowing effect.”
“Ad for 'Magic Burger'. Dynamic, exploded burger with all components (bun, patty, cheese, lettuce, tomato, sauce) suspended in mid-air. Emphasize photorealistic detail and a sense of motion. Dark, fiery background with glowing embers. Integrate text: 'MAGIC BURGER' as a prominent title, 'LIMITED TIME ONLY' as a secondary message, and '€6.99' in a starburst, all rendered with a fiery, glowing effect.”
“Use Image 1 as the exact pose reference and Image 2 as the character reference. Recreate the person/character from Image 2 in the exact dynamic pose and body position from Image 1. Keep the exact face, hair, clothing style/details, and expression from Image 2. Match the lighting and environment of Image 1. The final image must show the character from Image 2 performing the precise action/pose from Image 1 with perfect anatomy and natural integration.”
See how FLUX.2 [klein] 9B performs head-to-head against other AI models, ranked by community votes in blind comparisons.
FLUX.2 [klein] 9B starts at $0.006 per image through Lumenfall. Pricing varies by provider. Lumenfall does not add any markup to provider pricing.
You can use FLUX.2 [klein] 9B through Lumenfall's OpenAI-compatible API. Send requests to the unified endpoint with model ID "flux.2-klein-9b". Code examples are available in Python, JavaScript, and cURL.
FLUX.2 [klein] 9B is available through fal.ai and Replicate on Lumenfall. Lumenfall automatically routes requests to the best available provider.
FLUX.2 [klein] 9B supports images up to 2048x2048 resolution.
Generate images with custom prompts — no API key needed.
![FLUX.2 [klein] 9B — Photorealism](https://assets.lumenfall.ai/9Pi2UrOBgYuUua7NCANA1zW0hk-9WBtn9bL9LbipMWw/rs:fill:400:300/plain/gs://lumenfall-prod-assets/d3oncfxm7iebaynmda4br025isgw@jpeg)