What is Flux.2 Klein?

Klein is the open-weights line of Black Forest Labs' Flux.2 generation, released in 9B and 4B sizes. It is the successor to the Flux.1 family that most open image models were built on.

No. Generation runs on our GPU pool, so a laptop or phone browser is enough. A 9B model locally means a large download and a card with the VRAM to hold it.

Which Klein sizes can I use?

Both 9B and 4B, plus the community checkpoints and LoRAs built on either, of which there are more than 2,100 on Civitai today.

Can I edit images with Klein, not just generate?

Yes. The Klein node in ComfyUI covers generation, editing, inpainting, outpainting and face swap in one place.

How does Klein compare with Flux.1?

Flux.1 still has by far the larger community — roughly 25,000 models on Civitai against 2,100 for Klein — so Flux.1 wins on ecosystem while Klein is the newer architecture. Both are here, so judge on your own prompt.

Can I import a Klein model from Civitai?

Yes. Paste the model URL and Diffus imports it — weights, previews and trigger words — then puts it in the generator.

Plans start at $1/month and every plan is credit-based, so the cost of a generation is visible before you run it.

Black Forest Labs' Flux.2 line

Run Flux.2 Klein in Your Browser

Klein 9B and 4B, plus the 2,100+ community models built on them. No 9-billion-parameter download, no GPU, no environment to keep alive.

The difference, not the spec sheet

Why Run Klein Here

The weights are open. What is not free is the disk, the card and the afternoon of setup.

2,100+ Klein Models, Already Hosted

Community checkpoints and LoRAs built on Klein 9B and 4B are on disk and selectable. Paste a Civitai link to add one that isn't.

Browse models

One Node, the Whole Workflow

Generate, edit, inpaint, outpaint and face swap from a single self-contained Klein node in ComfyUI — no graph to assemble before the first image.

Open ComfyUI

Compare It Against the Rest

Flux.1, Flux Kontext, Qwen, SDXL and SD 3.5 are in the same session. Run one prompt through several and keep what wins.

Start generating

Core capabilities

What You Can Do With It

Generation is the first step, not the whole job.

Prompt to picture

Text to Image on Klein

Prompt Klein 9B for quality or 4B when you want the lighter model, at the aspect ratio you need, with the sampler and guidance already tuned for the Flux.2 line.

Start generating

Edit where you generate

Edit, Inpaint and Outpaint

The Klein node covers editing in the same place you generate — repaint a region, extend the frame, swap a face — without exporting and losing the parameters.

Open ComfyUI

Bring your own LoRAs

Stack Community LoRAs

Klein has its own growing LoRA ecosystem on Civitai. Import one by URL and stack it, or fine-tune your own here and use it the moment training ends.

Browse models