Meet the new Klein. Open weights. Native 4K. Explore the model

THE NEXT CHAPTER OF KLEIN

FLUX 3 Image Klein

A little model.
A bigger imagination.

Create from a thought. Edit with a reference.
Explore native 4K images, right in your browser.

Official BFL demo sample of a carefully lit still-life arrangement

From the official demo
Explore the examples ↓

Start creating for free

Official BFL demo hosted on Hugging Face. Independent guide. Queues and free GPU limits apply.

5.6B open weights4K native output10 reference images
↓

YOUR IDEAS, A NEW CANVAS

Try it free in your browser

One model for a blank canvas,
a small edit, or a whole new scene.

FLUX 3 Image KleinHosted on Hugging Face
Official demo sample: a carefully lit still-life arrangementExample from the official demo

A thought is all it takes

What will you make?

Use the official Black Forest Labs demo hosted on Hugging Face to enter a prompt, add references, and generate or edit an image. This site is an independent guide.

  • Text-to-image & image editing
  • Up to 10 reference photos
  • 1K, 2K & 4K settings

Loading connects to Hugging Face. Prompts and uploads go to that service. Free GPU quotas, queues and possible sign-in apply. Privacy details.

FROM A PROMPT TO A FILE

Make your first image in three steps

Begin with one clear idea and a small output. A simple first run makes it easier to judge the image and understand the hosted demo's limits.

01 / PREPARE

Describe a single scene

Choose a subject, setting, composition and light. For example, ask for a ceramic cup beside a window rather than several unrelated scenes in one request. The demo's prompt-upsample option expands a short request into a fuller scene caption; keep its ordinary default while learning the controls.

Start without references if you are testing text-to-image. For an edit, upload a photograph you have permission to use and say which detail should change. Assign a clear role to each extra reference rather than asking all of them to control the composition.

02 / GENERATE

Begin at 1K

Load the demo, enter your request and use the smaller resolution for a first draft. Keep the initial task modest while checking the subject, framing and text. A model's 4K capability does not guarantee that a free hosted session has enough GPU time for that workload.

If the service reports a queue, sign-in requirement or exhausted quota, follow its message. Repeated submissions do not guarantee a faster slot. You can also use the direct Hugging Face link below the tool if the embedded view cannot complete sign-in or load correctly.

03 / REVIEW

Inspect, then download

Read any lettering, check hands and small objects, and compare the result with your intended scene. For an edit, examine the areas that should have stayed unchanged as carefully as the part you asked to alter. Change one instruction at a time when refining the output.

Download the result from the demo when it is ready, and keep a copy with the prompt and settings you used. This guide does not keep your generation history or recover files from an external session. Increase resolution only after the smaller draft gives you a composition worth keeping.

If generation is unavailable, you can still explore the examples below and prepare a prompt. Hosted quota and availability are controlled by Hugging Face; this guide does not provide its own inference API.

GET TO KNOW THE MODEL

What is FLUX 3 Image Klein?

Released by Black Forest Labs on October 15, 2026, Klein brings image creation and editing into a compact open weights model.

01 / RESOLUTION

5.6B open weights, native 4K

Explore high-resolution detail with a smaller image transformer. Choose a distilled checkpoint for everyday experimentation or Base for fine-tuning.

02 / REFERENCES

Text-to-image + multi-reference editing

Create from words, edit a photo, or combine up to 10 references. Describe which image supplies the subject, composition or visual style.

03 / YOUR PROJECT

License & commercial use

The weights use the FLUX Kommunity License. Commercial eligibility and conditions depend on your organization and use. Read the full terms.

Read the model guide
Official demo sample: a designed record sleeve with detailed letteringOfficial BFL demo example

KEEP YOUR OWN WORKFLOW

How to run it locally

Prefer your own machine? Start with a compatible workflow and the right checkpoint. GPU memory depends on precision, the text encoder, resolution and references.

ComfyUI workflow

Follow the native template, component-folder map and first-run checks in the dedicated workflow guide.

Official ComfyUI setup ↗

Weights download

Choose a runtime and checkpoint, review gated access, and verify the supporting files before loading them.

Official model repository ↗

FOR YOUR NEXT BUILD

API & pricing

The free browser demo and paid API are separate services. Use the official API for an integration; check current resolution-based pricing before submitting a job.

Read the official quickstart ↗
POST /v1/flux-3-image-klein
{
  "prompt": "Your next idea, in detail",
  "aspect_ratio": "1:1"
}

Use a server-side key. This site does not collect API keys.

View current BFL pricing ↗

FIND YOUR FIT

FLUX 3 Image Klein
vs FLUX.2 Klein

Compare the published specifications and plan a repeatable test before changing a working setup. Looking for the older model itself? Start with the FLUX.2 Klein guide and official 4B demo.

Compare the Klein models
New Klein5.6BFLUX Kommunity License
FLUX.2 Klein4B / 9BCheckpoint-specific licenses

GIVE YOUR IDEA SOME DIRECTION

Prompting guide

Start with a subject, add the scene and light, then describe the finish. For edits, say what should change and what should stay.

01 / CREATE

A quiet product portrait

A single ceramic cup on warm limestone, soft morning light from the left, subtle glaze texture, understated editorial photography, no text.

02 / EDIT

Change one thing

In the first image, change only the jacket to deep forest green. Keep the person's pose, facial features, background and lighting unchanged.

03 / COMBINE

Give each reference a role

Use the subject from the first image in the setting of the second image. Match the soft light and muted colors of the third image.

These are starting prompts, not guarantees of a specific result. Paste one into the demo and refine it.

A few things to know

Frequently asked questions

Is the browser demo free?

Yes. Load Black Forest Labs' official Hugging Face demo on this page. Its free GPU quota, queue, availability and any sign-in requirements are controlled by Hugging Face. This website does not sell credits or charge for access.

Does the model support 4K output?

The model supports native 4K output. The official demo exposes 1K, 2K and 4K settings, but higher resolutions take longer and can exceed a free session's GPU quota. Start with 1K to test a prompt.

How many reference photos can I use?

The model supports up to 10 reference images. In the demo, open Reference images and upload them in the order you intend to describe. The first reference determines the output's shape.

Do I need to install anything?

No installation is needed for the browser demo. Running the weights on your own hardware is a separate option and requires compatible software and sufficient GPU memory.

Can I use the model commercially?

The weights use the FLUX Kommunity License. Qualifying users with less than US$5 million in annualized revenue, including affiliates, may generate commercial outputs subject to its conditions. Larger organizations need appropriate commercial terms. Read the full official license before use.

Is this the official Black Forest Labs website?

No. FLUX3Klein is an independent guide. The optional generator is the official Black Forest Labs demo hosted on Hugging Face. Prompts and reference files submitted there are handled by that third-party service; this guide does not operate its own AI inference API.

From an idea to an image

Make room for your next idea.

Try a prompt. Explore a reference. See what Klein can do.

Try FLUX 3 Image Klein