FLUX.2-klein-4B
Name in the API
black-forest-labs/FLUX.2-klein-4BBase model
black-forest-labs/FLUX.2-klein-4B Weights we run
The original weights, quantized to FP8 when they are loaded
Type
Image generation and editing
Input → output
text, up to 5 reference images → image
Availability
Dedicated Hardware
A 24 GB slice of a GPU per instance
Limits
Image size: at most 5,308,416 pixels (width × height), for example 3072×1728 or 2304×2304.
Editing with more than one reference image: at most 1024×1024 pixels.
Images per request (n): only 1. Send one request per image.
Steps (num_inference_steps): at most 50, default 16.
Endpoint
/v1/images/generations, /v1/images/editsExample
Generate an image , edit an image . Set model to the name above.
Notes
FLUX.2-klein-4B and FLUX.2-dev are fallbacks for each other.
FLUX.2-dev allows smaller images (at most 2048×2048), so a request above that size fails
if it ends up on the fallback.