Flux
Black Forest Labs' FLUX.2 family: exact hex colours, sharp typography and up to 8 reference pictures, from the sub-second Klein to the top-quality Max.
What it nails
- Exact colours from hex codes
- Designed-looking typography
- From sub-second Klein to top-quality Max
Watch out for
- Puts most weight on the first words: order matters
FLUX.2 is the image family from Black Forest Labs, the lab behind the FLUX models. Its secret weapon is control: it follows a hex colour code to the exact shade, reads text in quotes as typography, and pays the most attention to whatever you put first in the prompt.
The Lab runs four versions, from the sub-second Klein to Max, the highest-quality one.
At a glance: Flux. The live spec card, price calculator and Generate button show here on the site.
What FLUX.2 is secretly great at
Exact brand colours from hex codes
Write the colour as a hex code tied to an object: "sofa in deep teal hex #1B6B6F". FLUX.2 matches it, so your pictures stay on brand.
A modern living room with warm terracotta walls in hex #C4725A, a large L-shaped sectional sofa in deep teal hex #1B6B6F, and golden amber hex #E8A847 accent pillows, throw blanket, and a velvet ottoman. Light oak hardwood floors, a round marble coffee table with dried pampas grass in a glass vase, floor-to-ceiling windows with sheer white curtains letting in soft afternoon light, two potted fiddle leaf figs, and an abstract painting on the main wall featuring all three accent colors. Clean minimal composition, natural daylight casting soft shadows across the room.
Example by Black Forest Labs · source ↗
Create a vertical infographic about coffee consumption worldwide. Title: 'Global Coffee Culture'. Include 3 sections with statistics, use icons for each country, color scheme #4A2C2A (brown) and #F5E6D3 (cream). Modern minimalist style with clean typography.
Example by Black Forest Labs · source ↗
Typography that looks designed
Black Forest Labs built FLUX.2 for "complex typography, infographics, memes and UI mockups with legible fine text". Put the words in quotes and describe the lettering style.
Groovy retro poster with the quote 'If you love me let me sleep'. Bold 70s typography in deep red and warm pink tones. Cream background and bold orange doodle around the text. Funky layout with playful shadow. Style: bold vintage aesthetic, dopamine decor
Example by Black Forest Labs · source ↗
Style: Classic superhero comic Character: Worried scientist frantically typing on glowing holographic keyboard, face illuminated by blue light showing deep concern Setting: Massive computer server room with sparking circuits and red warning lights flashing on monitors Text: 'The AI models are corrupting! We need Diffusion Man!' Mood: Tense, urgent + dramatic blue and red tones
Example by Black Forest Labs · source ↗
Short prompts already look real
FLUX.2 [pro] and [max] quietly expand a short prompt into a detailed one before drawing, so one line can give a photo-quality result.
Soaking wet tiger cub taking shelter under a banana leaf in the rainy jungle, close up photo
Example by Black Forest Labs · source ↗
Precise edits on your own pictures
Upload a picture and say exactly what to add and where. FLUX.2 [pro] takes up to 8 reference pictures in the Lab; call them "image 1", "image 2" in the prompt.
Add the text 'By Black Forest Labs' below the main text in the middle of the book
Example by Black Forest Labs · source ↗ · This is an edit: add your own book cover as a reference picture first.
Which FLUX.2 to pick
| Version | Pick it for | Sizes in the Lab | References |
|---|---|---|---|
| FLUX.2 [pro] | Black Forest Labs' recommended default: production quality in under 10 seconds | 1K · 2K | Up to 8 |
| FLUX.2 [max] | The highest quality, for final assets | 1K · 2K | Up to 8 |
| FLUX.2 [flex] | The strongest at text and fine detail | 1K · 2K | Up to 8 |
| FLUX.2 [klein] 9B | Real-time drafts: sub-second pictures at the lowest price | 1K · 2K | Up to 4 |
Sketch the idea on [klein] for pennies, then run the winning prompt on [pro] or [max]. Klein does not expand your prompt, so give it a fuller description.
How to prompt FLUX.2
From Black Forest Labs' official FLUX.2 prompting guide.
- Order it Subject, Action, Style, Context. "FLUX.2 pays more attention to what comes first."
- Aim for 30 to 80 words for most pictures; 10 to 30 for quick ideas.
- No negative prompts. FLUX.2 does not support them. Write "sharp focus" instead of "no blur".
- Put text in quotation marks and say where it goes, its font and colour.
- Give colours as hex codes after the word "color" or "hex", tied to a specific object.
- For photos, name the camera and lens: "Shot on Fujifilm X-T5, 35mm f/1.4".
Each FLUX.2 run in the Lab makes one picture. For variations, run the prompt again or change one word at a time.
FAQ
Which FLUX.2 should I use?
[pro] for most work, [max] for final assets, [flex] for text-heavy designs, [klein] for fast, cheap drafts.
Can FLUX.2 match my brand colours?
Yes. Write the colour as a hex code next to the object it belongs to, for example "a mug in hex #1B6B6F".
Does FLUX.2 understand negative prompts?
No. Describe what you want to see instead of what you do not want.
Can I use my own pictures?
Yes. Upload up to 8 reference pictures (4 on [klein]) and refer to them as image 1, image 2 and so on.