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Image model vs image model

FLUX.2 Klein 4B vs FLUX.2 Klein 9B

People picked FLUX.2 Klein 9B’s picture over FLUX.2 Klein 4B’s about 63% of the time in blind votes. FLUX.2 Klein 4B costs 1.2× less ($0.005 against $0.006 an image), so it wins when “good enough” will do.

By ModelCompare ·

$0.005 and $0.006 a picture, paid from your credits. New accounts start with free credit.

At a glance

Longer bar means the bigger number. Elo bars start at 800.

Blind votes · how often people would pick each picture

FLUX.2 Klein 4B FLUX.2 Klein 9B

Price per image · 1024×1024, lower is better

FLUX.2 Klein 4B$0.005
FLUX.2 Klein 9B$0.006

Text to image · arena Elo, higher is better

FLUX.2 Klein 4B837
FLUX.2 Klein 9B929

Editing · arena Elo, higher is better

FLUX.2 Klein 4B938
FLUX.2 Klein 9B1015

Same prompt, both models

We give every image model the same fixed prompts and the same pictures to edit. Here is what FLUX.2 Klein 4B and FLUX.2 Klein 9B made. Each made one picture per prompt; nothing was picked or retouched.

Photo

“A cozy bookshop on a rainy Tokyo street at night, warm window light, reflections on wet pavement, 35mm film photo”

FLUX.2 Klein 4B’s picture for “A cozy bookshop on a rainy Tokyo street at night, warm window light, reflections on wet pavement, 35mm film photo”

FLUX.2 Klein 4B

FLUX.2 Klein 9B’s picture for “A cozy bookshop on a rainy Tokyo street at night, warm window light, reflections on wet pavement, 35mm film photo”

FLUX.2 Klein 9B

Text in image

“A minimalist logo for a coffee brand called "Orbit Roasters", flat vector, two colours, the name clearly lettered”

FLUX.2 Klein 4B’s picture for “A minimalist logo for a coffee brand called "Orbit Roasters", flat vector, two colours, the name clearly lettered”

FLUX.2 Klein 4B

FLUX.2 Klein 9B’s picture for “A minimalist logo for a coffee brand called "Orbit Roasters", flat vector, two colours, the name clearly lettered”

FLUX.2 Klein 9B

Product shot

“A glass perfume bottle on wet black stone, soft studio lighting, water droplets, high-end product photography”

FLUX.2 Klein 4B’s picture for “A glass perfume bottle on wet black stone, soft studio lighting, water droplets, high-end product photography”

FLUX.2 Klein 4B

FLUX.2 Klein 9B’s picture for “A glass perfume bottle on wet black stone, soft studio lighting, water droplets, high-end product photography”

FLUX.2 Klein 9B

Image edit

The picture both models were asked to edit

Asked to edit this picture: “Make it a snowy winter morning. Keep the bookshop, the street and the camera angle the same.”

FLUX.2 Klein 4B’s picture for “Make it a snowy winter morning. Keep the bookshop, the street and the camera angle the same.”

FLUX.2 Klein 4B

FLUX.2 Klein 9B’s picture for “Make it a snowy winter morning. Keep the bookshop, the street and the camera angle the same.”

FLUX.2 Klein 9B

Edit with people

The picture both models were asked to edit

Asked to edit this picture: “Move them to a beach at sunset. Keep all three people's faces, expressions, hair and clothes exactly the same.”

FLUX.2 Klein 4B’s picture for “Move them to a beach at sunset. Keep all three people's faces, expressions, hair and clothes exactly the same.”

FLUX.2 Klein 4B

FLUX.2 Klein 9B’s picture for “Move them to a beach at sunset. Keep all three people's faces, expressions, hair and clothes exactly the same.”

FLUX.2 Klein 9B

Try your own prompt on both

Where they sit among all 56 image models

Up and to the left is better pictures for less money. Hover or tap a dot for its numbers, then click it to compare that model with FLUX.2 Klein 4B. Models the arena hasn’t rated yet sit in the grey lane at the bottom.

Quality: Elo from the Artificial Analysis text-to-image arena. Price: one 1024×1024 image, on a log scale. The dashed line joins the best picture you can get at each price.

Which one to pick

Pick FLUX.2 Klein 4B if

  • price matters: 100 images cost $0.50, against $0.60 with FLUX.2 Klein 9B

Pick FLUX.2 Klein 9B if

  • you want the better picture: in blind votes people chose its image over FLUX.2 Klein 4B’s about 63% of the time
  • you mostly edit pictures: it scores higher in the editing arena (Elo 1015 against 938)

See what both make of your prompt

The specs

Spec FLUX.2 Klein 4B FLUX.2 Klein 9B
Price per image$0.005 ($0.02 per edit)$0.006 ($0.022 per edit)
100 images$0.50$0.60
Text-to-image Elo837 ±12 (#96 in the arena)929 ±10 (#75 in the arena)
Editing Elo938 ±17 (#62 in the arena)1015 ±13 (#43 in the arena)
Arena votes6,41810,730
Edits uploaded picturesYesYes
Largest size——
Open weightsYesYes
Zero data retention——
LabBlack Forest LabsBlack Forest Labs
Official nameFLUX.2 [klein] 4BFLUX.2 [klein] 9B
ReleasedJanuary 2026January 2026

Elo ± is the 95% margin. Prices are for one 1024×1024 image from fal.ai.

Questions

Which is better, FLUX.2 Klein 4B or FLUX.2 Klein 9B?

People picked FLUX.2 Klein 9B’s picture over FLUX.2 Klein 4B’s about 63% of the time in blind votes. FLUX.2 Klein 4B costs 1.2× less ($0.005 against $0.006 an image), so it wins when “good enough” will do.

Which is cheaper, FLUX.2 Klein 4B or FLUX.2 Klein 9B?

FLUX.2 Klein 4B: $0.005 for a 1024×1024 image, against $0.006 for FLUX.2 Klein 9B. 100 images cost $0.50 and $0.60.

Can FLUX.2 Klein 4B and FLUX.2 Klein 9B edit images?

Yes, both can change a picture you upload. In the Artificial Analysis editing arena FLUX.2 Klein 4B has an Elo of 938 and FLUX.2 Klein 9B 1015.

How can I compare FLUX.2 Klein 4B and FLUX.2 Klein 9B myself?

Open the comparison, type one prompt and both models draw it side by side, each with what it cost and how long it took. You sign up with Google before your first run, and new accounts start with free credit.

Still deciding? Send one prompt to both and see the pictures side by side, with what each one cost. Compare FLUX.2 Klein 4B and FLUX.2 Klein 9B →

Where the numbers come from

Quality scores are Elo ratings from the Artificial Analysis image arenas, where people vote between two pictures made from the same prompt without knowing which model made which. The vote split comes from the Elo gap. Prices are for one 1024×1024 image from fal.ai; models billed per token are estimated at the quality the arena scored. The sample pictures are our own runs. Updated October 25, 2026.