FLUX 3 Image Klein Download: Weights and ComfyUI

FLUX 3 Image Klein has official downloadable weights. Black Forest Labs released both base and distilled versions on October 15, 2026, alongside a ComfyUI distribution. Start with the exact repository for your intended runtime; a checkpoint from an older Klein release is a different model. This guide checks the public sources as of October 21, 2026. ^[1]

Where to download FLUX 3 Image Klein

Use the repositories linked from Black Forest Labs’ own model documentation:

These are separate download targets. Choose the ComfyUI package for its workflow rather than assuming a library-oriented repository contains drop-in files for every loader. If Hugging Face asks you to sign in or accept access conditions, complete that process on the official repository. A failed unauthenticated download does not mean that the model was withdrawn. ^[2]

Base and distilled are different starting points

The release includes a base checkpoint for further training and a distilled checkpoint for faster generation. Both have 5.6 billion parameters. BFL also announces quantized builds, so the checkpoint name and precision matter when choosing files for your hardware. ^[1]

Do not transfer sampler settings merely because two files share the word Klein. BFL lists sixteen steps for distilled and fifty for base. Its guidance settings also differ. Load a workflow written for the selected checkpoint and keep its defaults while checking the first result. ^[2]

Use the official ComfyUI workflow as the file manifest

Update ComfyUI and open a fresh Klein template before downloading missing components. The official editing workflow includes notes that identify its checkpoint, encoders, VAE, and storage folders. At the checked revision, its base INT8 setup lists:

ComfyUI/models/
  diffusion_models/
    flux3-image-klein-base-int8-convrot.safetensors
  text_encoders/
    qwen3.5_9b_flux3_prompt_upsampler_w4a8.safetensors
    qwen3vl_4b_int8_convrot.safetensors
  vae/
    flux2-vae.safetensors

This is the file set for that particular template, not a universal list for every Klein workflow. The template uses fifty steps, CFG 3.5, and the Euler sampler with a simple schedule. Its edit setup scales the reference to roughly one megapixel; increasing reference detail changes the resource requirements. ^[3]

A practical first check is whether every loader resolves its named file. Only after that should you diagnose the prompt or sampling behavior. If a loader is missing, compare your installed ComfyUI version with the template’s requirements before adding unrelated custom nodes.

Keep prompt upsampling in the workflow

BFL emphasizes that Klein is trained on detailed scene captions. Its reference command-line implementation runs the prompt upsampler by default, while its documented Diffusers pipeline needs that separate step to be called explicitly. A short edit instruction passed directly to the image model is therefore a different setup from the recommended pipeline. ^[2]

For an initial test, keep the template intact. Change one prompt, use a reference you have permission to process, and save the workflow together with the result. Record the exact checkpoint names as well; a screenshot of the final image alone is not enough to reproduce the setup.

Local files and hosted access serve different needs

A local workflow gives you responsibility for model files, hardware, runtime versions, and the applicable license. BFL publishes the release under the FLUX Kommunity License; review the current terms linked from the model repository for your intended use. Downloadable weights alone do not establish unrestricted commercial permission. ^[1]

If you want to use the hosted model without installing weights, the FLUX 3 Image Klein page provides a Playground and live prices. The API reference documents the hosted request fields separately. Local checkpoint settings and hosted API fields are not interchangeable: use the contract for the interface you are actually calling.

Hosted showcase: three photographic directions

These three original FLUX 3 Image Klein outputs explore portrait lighting, architectural space, and close-up material detail. Each was generated without a reference image at 1K, 3:2, sixteen steps, and safety tolerance 2, returning a 1248 × 832 JPEG. Seeds were 137, 281, and 419 respectively. They demonstrate hosted generation; they do not establish equivalence with a particular local checkpoint.

After the rain

Scarlet silk, a white calla lily, and rain-lit streets give this cinematic portrait its visual focus.

A cinematic fashion editorial photograph, landscape 3:2. An adult East Asian woman in a sculptural scarlet silk evening dress is caught mid-turn beneath the canopy of a small late-night flower shop on a rain-soaked city street. Waist-up three-quarter framing, face clearly visible, an intent glance back toward the camera, a few damp strands of black hair across her cheek. She holds a single white calla lily low against the red fabric. Warm tungsten light spills from the shop onto one side of her face; cool petrol-blue street light and rain form the background. A moving taxi makes one soft amber streak far behind her. The red silk catches a gust, creating a strong diagonal through the lower frame. Shot like a high-end film still on a 50mm lens, shallow depth of field, believable skin pores and fabric weave, rich restrained color, deep but detailed shadows, fine film grain. Intimate, dramatic, editorial, not a beauty retouch. No readable signage, no text, no logos, no watermark.

A room above the sea

Warm travertine arches frame a cobalt horizon, with reflected light drawing the eye through the cliffside retreat.

An exceptional architectural magazine photograph of a sculptural Mediterranean cliff house at blue hour, landscape 3:2. View from a shaded limestone terrace through a monumental curved opening toward a cobalt sea and a distant pale horizon. A narrow infinity pool runs diagonally from the foreground toward the ocean, its perfectly still surface reflecting a single warm illuminated arch. One low rust-colored linen lounge chair gives human scale; no people. The building is carved from warm ivory travertine with tactile pores and softly rounded edges, not shiny futuristic plastic. A sparse olive branch enters from the upper corner. Precise architectural perspective, 24mm tilt-shift lens, strong foreground-to-background depth, carefully balanced negative space, realistic indirect amber interior lighting against deep blue dusk, quiet luxury and a memorable sculptural silhouette. Photorealistic material detail, no overprocessed HDR, no text, no logos, no watermark.

Emerald in the shadows

Hard light reveals emerald facets, brushed gold, and wet volcanic stone in a tightly framed jewelry campaign.

A striking luxury jewelry campaign macro photograph, landscape 3:2. A single sculptural brushed-gold ring with a large emerald-cut forest-green gemstone rests at an angle on wet black volcanic stone. Very tight composition: the gemstone and its precise geometric facets dominate the frame, ring band receding behind it. One small bead of water clings to the gold edge. A razor-thin shaft of hard morning light enters from the upper left, making a luminous green reflection on the wet stone and bright clean highlights on only a few facets; the rest falls into rich charcoal shadow. Tiny natural mineral texture, physically believable refraction, subtle gold micro-scratches, premium still-life art direction. Shot on a 100mm macro lens with selective focus across the gem, strong diagonal geometry, emerald green and warm gold against almost black. No glitter cloud, no decorative props, no text, no logos, no watermark.

A hosted three-image check

To make the hosted option concrete, we generated one product image, edited it with one reference, then submitted both results as ordered references on October 21, 2026. These are hosted results, not a benchmark of the ComfyUI checkpoint above. All three used the same settings:

{
  "model": "flux-3-image-klein",
  "resolution": "1k",
  "aspect_ratio": "3:2",
  "steps": 16,
  "seed": 42,
  "safety_tolerance": 2,
  "output_format": "jpeg",
  "n": 1
}

Each returned a 1248 × 832 JPEG. The images below are the original outputs; open an image to inspect the full file. A seed records one input to the request, not a guarantee that another runtime or checkpoint will reproduce these pixels.

1. Generate the product scene

An unlabelled amber glass bottle on pale limestone, soft morning window light, warm neutral background, space beside the bottle, no text or logos. Product photography, landscape composition.

The result places an amber bottle on pale stone with space to its right. No reference image was supplied.

2. Edit the background

Change the background to deep midnight blue. Preserve the amber glass bottle, the pale limestone surface, the camera angle and the direction of the soft light. No text or logos.

The request used the first output as the only image_urls entry. The backdrop becomes dark blue while the bottle, stone surface, and rightward shadow remain recognizable. Preservation is visual, not pixel-identical.

3. Combine two ordered references

Use the bottle and pale limestone surface from Image 1 and the midnight blue background from Image 2. Place the bottle in the left third of a landscape composition, with generous empty space on the right. Match perspective and lighting. No text or logos.

The request used the first and second outputs as image_urls, in that order. The output keeps the dark backdrop and the bottle near the left third. Its composition is very close to the single-reference edit; this example does not demonstrate a large layout change or prove how much each reference influenced the result.

Frequently asked questions

Where can I download FLUX 3 Image Klein weights?

Use the Black Forest Labs repositories listed above for the base, distilled, ComfyUI and prompt-upsampler files. Check the exact repository and checkpoint name before downloading; earlier Klein releases are different models.

Which files do I need for ComfyUI?

Open the official workflow for your chosen checkpoint and use its loader names and notes as the file checklist. The INT8 base example above is specific to that template; it is not a universal list for every Klein workflow.

Can I use local checkpoint settings in the hosted API?

Local checkpoint settings and hosted request fields are separate contracts. Follow the API reference for hosted requests. The photographs in this guide show hosted outputs; they do not establish equivalence with a local checkpoint or benchmark its hardware requirements.

What this guide verifies

The download locations and workflow file names above were checked against first-party sources. We have not benchmarked the local workflow or validated its memory use on a particular GPU. Choose a precision and resolution using the current workflow guidance, then measure on your own hardware before planning a larger run.

Sources

1. Black Forest Labs: FLUX 3 Image Klein release.
2. Black Forest Labs: Klein model documentation.
3. Comfy-Org: official Klein editing workflow.