FLUX.2 [flex] vs FLUX.2 [klein] 9B

FLUX.2 [flex] from Black Forest Labs and FLUX.2 [klein] 9B from Black Forest Labs, run on the same six prompts. Which one is better depends on the prompt, so the images are the comparison; the facts below are what differs regardless of prompt.

What differs

FLUX.2 [flex] costs 2 credits per megapixel, 2× the 1 credit of FLUX.2 [klein] 9B.
ImageForge lists Typography as a strength of FLUX.2 [flex] but not of FLUX.2 [klein] 9B.
ImageForge lists Fast as a strength of FLUX.2 [klein] 9B but not of FLUX.2 [flex].

	FLUX.2 [flex]	FLUX.2 [klein] 9B
Provider	Black Forest Labs	Black Forest Labs
Credits per megapixel	2	1
Refinement	Yes	Yes
Native aspect ratios	10 of 10	10 of 10
Listed strengths	Typography	Fast

Same prompt, both models

Unedited, at 1 megapixel, with the exact prompt each pair was given. How we ran the test.

Photorealism

What to look for: skin texture, natural light and a believable shallow depth of field.

“Close-up portrait of an elderly fisherman with a weathered face and grey stubble, wearing a yellow raincoat, soft overcast light from a window, shallow depth of field, 85mm photograph”

Text rendering

What to look for: both lines of text spelled correctly and placed on the sign, not floating beside it.

“A vintage enamel sign on a brick wall that reads "FRESH BREAD DAILY" in bold red serif letters, with "since 1962" in smaller script below, morning sunlight”

Product shot

What to look for: glass, metal and water rendered convincingly in one studio setup.

“A frosted glass perfume bottle with a brass cap on wet black slate, droplets on the glass, soft rim light, reflections on the stone, studio product photography”

Prompt adherence

What to look for: exactly three red cubes on the sphere, with the cone on the left and the cylinder on the right.

“Three red cubes stacked on top of a blue sphere, a green cone to the left and a yellow cylinder to the right, on a black and white checkerboard floor, soft studio lighting”

Illustration

What to look for: a consistent watercolor-and-ink style rather than a photo with a filter.

“Children's book illustration of a fox in a knitted scarf reading a book under a large mushroom in light rain, soft watercolor and ink, warm palette”

Complex scene

What to look for: mixed light sources, wet reflections and several subjects in one frame.

“A narrow street in Tokyo at night after rain, neon signs reflecting in puddles, a cyclist with an umbrella passing a lit ramen shop, cinematic”

Sending one prompt to several models at once is part of the Basic and Pro plans.