AI TOOLS RADAR
Submit
All models / BLACK-FOREST-LABS
black-forest-labs logo
black-forest-labs

Black Forest Labs: FLUX.2 Klein 4B

Source description (English)

FLUX.2 [klein] 4B is the fastest and most cost-effective model in the FLUX.2 family, optimized for high-throughput use cases while maintaining excellent image quality. Pricing is based on the output...

View source on OpenRouter Hugging Face
Overview

Model specifications

Context
40,960 tokens
Maximum output
36,864 tokens
Architecture
text+image->image
Tokenizer
Other
Knowledge cutoff
Not provided
Moderated
No
OPENROUTER

Complete pricing

Synchronized OpenRouter rates. Token prices are shown per one million tokens.

Image output
$0.014
per megapixel
API

Quick start

Set OPENROUTER_API_KEY locally. Python requires requests; JavaScript runs in Node.js. Keep the key on the server.

API documentation

curl --fail-with-body https://openrouter.ai/api/v1/images \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"black-forest-labs/flux.2-klein-4b","prompt":"A sunlit mountain landscape"}'
Capabilities

Input → Output

Input
textimage
Output
image
API

Supported API parameters

seed
Available providers

1 Provider

Checked: September 7, 2026

Live providers on OpenRouter

Provider availability, latency, throughput and routing can change continuously. Open the source page for current operational data.

OpenRouter

Black Forest Labs

Not provided
Context
41K
Maximum output
37K
black-forest-labs

4 models

All models
black-forest-labs logoblack-forest-labs

Black Forest Labs: FLUX Video Edit

FLUX Video Edit [fast] takes a source video and an edit prompt and returns a precisely edited video. Add, remove, or replace objects and characters, rebuild the setting, edit on-screen...

Context
Not provided
Input
text · video
Output
video
Video Edit Output: $0.03 per second
View model details →
black-forest-labs logoblack-forest-labs

Black Forest Labs: FLUX Video Upscale

FLUX Video Upscale is a video upscaling model from Black Forest Labs. It enlarges a single source video by 1.5× to 3× while preserving its duration, with an optional prompt...

Context
Not provided
Input
text · video
Output
video
Video Upscale Output: $0.075 per megapixel-second
View model details →
black-forest-labs logoblack-forest-labs

Black Forest Labs: FLUX.3 Video

FLUX.3 Video is a video generation model from Black Forest Labs. It supports text-to-video, image-guided generation with opening and closing keyframes, and video continuation workflows, making it suited for controlled...

Context
Not provided
Input
text · image · video
Output
video
Video output: $0.17 per second
View model details →
black-forest-labs logoblack-forest-labs

Black Forest Labs: FLUX.2 Max

FLUX.2 [max] is the new top-tier image model from Black Forest Labs, pushing image quality, prompt understanding, and editing consistency to the highest level yet. Pricing is as follows, [per...

Context
47K
Input
text · image
Output
image
Image output: $0.07 per megapixel
View model details →