IMAGEBlack Forest Labs · from 7 credits / image
The small model of the FLUX 3 generation
FLUX 3 Klein Image Generator and Editor Online
Text to image and edits. 10 references. 1K, 2K or 4K.
Black Forest Labs built FLUX 3 Klein to carry FLUX 3's generation, editing and multi-reference skills in a 5.6B model. Run it in the browser on PicX Studio, with no weights to download and no GPU to set up.
- 1K–4K
FLUX 3 quality, Klein size
A FLUX 3 model at 5.6B parameters
Klein is the image model of the FLUX 3 family, cut down to 5.6B generator parameters. In Black Forest Labs' own blind tests it scores ahead of FLUX.2 [klein] 9B for both text to image and editing while using 38% fewer parameters.
Write it like a caption
Black Forest Labs trained Klein on full scene descriptions. PicX sends your prompt exactly as you write it, with no automatic rewrite, so a paragraph that covers subject, setting, light, lens and mood gets much more out of it than five keywords.
Up to 4K, in nine shapes
Choose 1K, 2K or 4K and one of nine aspect ratios, from 21:9 banners to 9:21 phone screens. For edits, auto keeps the shape of your first reference.
FLUX 3 Klein
Text to image and edits. 10 references. 1K, 2K or 4K.
Where a small FLUX earns its keep
Quick product edits Upload a product shot and ask for a new background, a sticker version or a seasonal look in one sentence.
Posters and print at 4K Render layouts and illustrations at 4K when the image has to hold up on a wall or in print.
Compositing from references Combine up to ten images, such as a product, a model and a location, and describe how they come together.
Testing before you self-host Klein's weights are open. Try your prompts here before you set up ComfyUI or Diffusers on your own GPU.
Why pick FLUX 3 Klein
- 5.6BGenerator sizeSmallest open model in BFL's launch evals.
- 10Reference imagesEdit one photo or blend several.
- 4KTop resolution1K, 2K or 4K output.
- +91Elo over FLUX.2 Klein 9BText to image, BFL's own blind evals.
- LowCost per imageBelow FLUX.2 on PicX. See the table.
- OpenWeightsSame model you can run locally.
What FLUX 3 Klein costs
Billed per image, at the resolution you pick. The same prices the generator shows before you run it.
- 1K7credits / imageOn Starter≈ 514 images / mo
- 2K10credits / imageOn Starter≈ 360 images / mo
- 4K26credits / imageOn Starter≈ 138 images / mo
Every model on every planCredits never expireSee plans
Pay for FLUX 3 Klein with crypto
Buy credits with Bitcoin, USDT, USDC, ETH, Solana and more — no card, nothing auto-renews, packs from $5, and 15% extra credits on crypto payments.
FLUX 3 Klein vs FLUX.2
Both are Black Forest Labs models you can use on PicX. Klein is the newer generation and the cheaper one; FLUX.2 offers Pro and Flex tiers.
Bounding-box layout, LoRA fine-tunes and the Klein base checkpoint are offered by Black Forest Labs but are not available on PicX yet. Live credit prices are in the pricing table.
How to use FLUX 3 Klein in 3 steps
- 1
Add references to edit (optional)
Upload up to ten images. One image and an instruction gives an edit; several images let you combine a product, a person and a place.
- 2
Write a full description
Describe the whole scene in sentences: subject, setting, light, camera and mood. For edits, write an instruction such as "Swap the desk lamp for a brass one and dim the room to evening".
- 3
Pick size and generate
Choose an aspect ratio and 1K, 2K or 4K. Draft at 1K, then rerun the one you like at 4K.
FLUX 3 Klein prompts to copy
Real prompts and what they made. Copy one, or open it in the generator with the model already picked.
Spice market
Overhead shot of a stall in a Moroccan spice market at noon: tall cone-shaped mounds of turmeric, paprika, cumin and dried rose petals in woven baskets, a dented brass scoop resting in the saffron, a vendor's hand reaching into frame, hard sunlight through a striped awning casting bands of shadow, rich grainy textures, documentary photography
Watch on volcanic rock
Studio product photograph of a steel diving watch with a black ceramic bezel lying on wet black volcanic rock, a wave splash frozen mid-air behind it, droplets beading on the sapphire crystal, a single hard rim light from the left and a soft blue fill, deep black background, shallow depth of field, shot on a 100mm macro lens
Fantasy map
A hand-drawn fantasy world map on aged, coffee-stained parchment with torn edges: snow-capped mountain ranges in fine ink hatching, dark green forests in watercolour washes, a coastline with a sea serpent curling between ships, a large ornate compass rose in the lower right corner, warm candlelight from above, seen flat from directly overhead
Event flyer
A minimal Swiss-style poster for a design festival on off-white paper: a strict 12-column grid, one huge red circle overlapping the top-left corner, oversized black numerals "26" set in a bold grotesque typeface, a thin black rule and the words "Design Week" in small caps below, lots of empty space, printed flat and photographed straight on
Templates to start from
Browse all templates
FLUX 3 Klein questions
What is FLUX 3 Klein?
FLUX 3 Klein (Black Forest Labs calls it FLUX 3 Image Klein) is a 5.6B-parameter open-weights image model released on 15 October 2026. It creates images from text, edits images from an instruction and combines up to ten reference images, at up to 4K.
What changed from FLUX 2 Klein?
FLUX 3 Klein is a 5.6B model from the newer FLUX 3 generation. Black Forest Labs reports it beats FLUX.2 [klein] 9B by 91 Elo in text to image and 70 Elo in editing in its own blind evaluations, with 38% fewer parameters. PicX offers FLUX 3 Klein, not FLUX.2 [klein].
How do you prompt FLUX Klein?
Write a full description, not a keyword list. Black Forest Labs trained Klein on long scene captions and says raw short prompts give noticeably weaker results. PicX sends your prompt as written, so cover the subject, setting, light, camera and mood in a few sentences. For edits, write a plain instruction like "Replace the background with a foggy pine forest".
Can FLUX Klein edit images?
Yes. Upload one image and describe the change, or upload up to ten to combine several subjects or styles into one picture. With the aspect ratio on auto, the result keeps the shape of the first image. Region editing with bounding boxes, which Black Forest Labs offers in its own tools, is not available on PicX yet.
FLUX Klein vs Krea 2 and Qwen Image: which is better?
In Black Forest Labs' launch evaluations, Klein ranked ahead of Qwen-Image 2.1 (7B) and Krea 2 (12.9B) while being the smallest of the three. Those are the maker's own tests. Krea 2 does not edit images, so it was left out of the editing comparison. The fairest check is to run the same prompt on Klein and on Qwen Image here.
Can I use LoRAs or ComfyUI workflows with FLUX 3 Klein on PicX?
Not yet. LoRA training, the base checkpoint and ComfyUI workflows are for running Klein's open weights on your own GPU. PicX runs the hosted model: you write a prompt, add references and pick a size.
Is FLUX Klein free?
The weights are free to download and run on your own GPU under the FLUX Kommunity License. On PicX, Klein is hosted and uses credits per image instead, so there is nothing to install. New accounts get one free image after sign-up, made with Nano Banana 2, our free-tier model, and credits never expire.
Is FLUX 3 Klein free for commercial use?
The FLUX Kommunity License that covers Klein's downloadable weights allows free commercial use for individuals and companies under $5M in annual revenue; larger organisations need a self-hosting licence or Black Forest Labs' API. On PicX you don't run the weights yourself: you generate through a hosted service and pay credits per image.
Try FLUX 3 Klein
FLUX 3 images and edits, up to 4K, in your browser.