Image model vs image model
FLUX.2 Klein 4B vs FLUX1.1 [pro] Ultra
People rate their pictures about the same in blind votes, so the cheaper FLUX.2 Klein 4B is the better buy: $0.005 against $0.06 an image.
At a glance
Longer bar means the bigger number. Elo bars start at 800.
Price per image · 1024×1024, lower is better
Text to image · arena Elo, higher is better
Same prompt, both models
We give every image model the same fixed prompts. Here is what FLUX.2 Klein 4B and FLUX1.1 [pro] Ultra 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
![FLUX1.1 [pro] Ultra’s picture for “A cozy bookshop on a rainy Tokyo street at night, warm window light, reflections on wet pavement, 35mm film photo”](/image-samples/bfl__flux-pro-1.1-ultra/street.webp)
FLUX1.1 [pro] Ultra
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.
Which one to pick
Pick FLUX.2 Klein 4B if
- price matters: 100 images cost $0.50, against $6.00 with FLUX1.1 [pro] Ultra
- you need to edit pictures you upload; FLUX1.1 [pro] Ultra only makes new ones here
- you want open weights you can run yourself
The specs
| Spec | FLUX.2 Klein 4B | FLUX1.1 [pro] Ultra |
|---|---|---|
| Price per image | $0.005 ($0.02 per edit) | $0.06 |
| 100 images | $0.50 | $6.00 |
| Text-to-image Elo | 837 ±12 (#96 in the arena) | 855 ±19 (#93 in the arena) |
| Editing Elo | 938 ±17 (#62 in the arena) | Not scored yet |
| Arena votes | 6,418 | 2,284 |
| Edits uploaded pictures | Yes | No |
| Largest size | — | — |
| Open weights | Yes | No |
| Zero data retention | — | No |
| Lab | Black Forest Labs | Black Forest Labs |
| Official name | FLUX.2 [klein] 4B | FLUX1.1 [pro] Ultra |
| Released | January 2026 | November 2024 |
Elo ± is the 95% margin. Prices are for one 1024×1024 image from the Vercel AI Gateway and fal.ai.
Questions
Which is better, FLUX.2 Klein 4B or FLUX1.1 [pro] Ultra?
People rate their pictures about the same in blind votes, so the cheaper FLUX.2 Klein 4B is the better buy: $0.005 against $0.06 an image.
Which is cheaper, FLUX.2 Klein 4B or FLUX1.1 [pro] Ultra?
FLUX.2 Klein 4B: $0.005 for a 1024×1024 image, against $0.06 for FLUX1.1 [pro] Ultra. 100 images cost $0.50 and $6.00.
Can FLUX.2 Klein 4B and FLUX1.1 [pro] Ultra edit images?
FLUX.2 Klein 4B can change a picture you upload. FLUX1.1 [pro] Ultra only makes new pictures from a prompt here.
How can I compare FLUX.2 Klein 4B and FLUX1.1 [pro] Ultra 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.
Related comparisons
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 the Vercel AI Gateway and 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.