FLUX 2: what FLUX.2 pro, flex, max, dev and klein can do — versions, pricing and prompts

What is FLUX 2

FLUX.2 is the second generation of image models from the German lab Black Forest Labs (BFL). It launched on November 25, 2025, and was the first to combine generation and editing in a single architecture: a 24-billion-parameter vision-language model understands the prompt and the images, and a rectified flow transformer renders the result. For the whole FLUX family, see the FLUX overview.

The generation has five versions:

• FLUX.2 [pro] — the production workhorse, generating in under 10 seconds;
• FLUX.2 [flex] — with manual control over step count (up to 50) and guidance, the strongest at typography;
• FLUX.2 [max] — top quality plus web search for up-to-date details;
• FLUX.2 [dev] — 32-billion-parameter open weights for non-commercial use;
• FLUX.2 [klein] — compact 4B and 9B models released in early 2026, the fastest in the family.

Since July 2026, BFL has a next generation: FLUX 3. FLUX.2 remains in the API and is still BFL’s most popular open model for running locally.

What FLUX 2 can do

Up to 4 MP at any aspect ratio. Every version generates and edits images up to 4 megapixels — roughly 2048 × 2048 for a square.

Up to 10 references. A character, a product and a style from different images in one scene. In the API, pro and max are limited to 8 images, the BFL playground allows 10, and klein takes 4.

Hex color control. You can specify an exact color: “a #E3B23C glaze on a #2F3E46 backdrop.” For brand assets and product shots, that saves rounds of edits.

Text, infographics and UIs. BFL says complex typography, memes, infographics and UI mockups with small text now work reliably in production. flex handles text best.

Photorealism. Cleaner detail, sharper textures, steadier lighting — BFL singles out product and photo work.

Web search in max. FLUX.2 max pulls current information from the web straight into the image — for example, the look of a building or a product.

FLUX 2 pro vs. flex vs. max vs. dev vs. klein

	pro	flex	max	dev	klein 4B / 9B
Access	API	API	API	open weights	open weights and API
Best for	production volume	text, fine control	top quality	running locally	speed, real time
API price	$0.03 per MP, edits $0.045	$0.05 per MP, edits $0.10	$0.07 per MP	free, non-commercial	from $0.014 / $0.015
References	8 in the API	—	8 in the API	—	up to 4
Notable	under 10 s	up to 50 steps, guidance	web search	32B parameters	sub-second generation
License	—	—	—	non-commercial	4B — Apache 2.0, 9B — non-commercial

Klein 4B fits in about 13 GB of VRAM — an RTX 3090 or 4070 and up. The base klein 9B needs about 29 GB and an RTX 4090. Klein 9B is a 9B flow model with an 8B Qwen3 text embedder, distilled down to 4 inference steps.

What FLUX 2 is good for

• Product photography and catalogs with exact brand colors via hex.
• Series with one product or character — up to 10 references.
• Posters, memes and infographics — best on flex.
• UI mockups for decks and prototypes.
• Local generation and LoRA training — dev and klein on your own GPU.

FLUX 2 vs. alternatives

	FLUX 2	FLUX 3 Image	Nano Banana Pro	Qwen Image
Developer	Black Forest Labs	Black Forest Labs	Google DeepMind	Alibaba
Max size	4 MP	4K	4K	2K (2048 × 2048)
References	up to 10	up to 10	up to 14	1–10
Open weights	dev, klein	Klein	no	1.x, Layered, 2.1
Hex colors	yes	yes	no	—
In AI2Face	yes	yes	yes	yes

FLUX 2 is the best choice when you need an open model or exact hex colors. FLUX 3 Image adds 4K and box-based editing, and Nano Banana Pro is best at likeness from photos of people.

How to write prompts for FLUX 2

1. Order by importance: main subject → action → style → context. Put what matters most at the start.
2. Use hex codes for colors: “exactly #E3B23C.” Use separate codes for the background and the object.
3. Quote text and give it a role: headline, subheading, caption. For complex typography, use flex.
4. Number references and give them roles: “the product from image 1, the background from image 2.”
5. Describe complex scenes in parts: BFL says FLUX.2 follows structured, multi-part prompts better than earlier versions.

The full prompts for each image are in the gallery.

How to use FLUX 2 in AI2Face

FLUX 2 is in the AI2Face generator next to FLUX 3, Nano Banana Pro and GPT Image 2.5.

1. Sign up — new accounts get starter credits.
2. Open the generator and pick FLUX 2.
3. Write a prompt, and upload references if needed.
4. The credit cost is shown before you start. Credits don’t expire.

The images on this page were made in AI2Face with Nano Banana Pro from FLUX.2-style prompts — they show how such prompts work, not FLUX 2’s own output quality.

Limitations

• 4 MP is the ceiling. For 4K, use FLUX 3 Image or Nano Banana Pro.
• Reference limit in the API. pro and max take 8 images, not 10.
• Open-weight licenses. dev and klein 9B are non-commercial only; commercial use needs a separate BFL license. Only klein 4B is free to use.
• Hardware for local runs. Even the compact klein 4B needs about 13 GB of VRAM.
• No longer the newest. In BFL’s internal tests, the compact FLUX 3 Image Klein beats FLUX.2 pro.

Bottom line

FLUX 2 is a workhorse for product shots, brand colors and posters: hex codes, 10 references and 4 MP cover most commercial jobs, and dev and klein run on your own hardware. For 4K and precise box-based edits, move to FLUX 3. For portraits and facial likeness from photos, compare the result with Nano Banana Pro in the same AI2Face generator.