Image model vs image model
FLUX.2 Klein 4B vs Nano Banana (Gemini 2.5 Flash Image)
People picked Nano Banana (Gemini 2.5 Flash Image)’s picture over FLUX.2 Klein 4B’s about 70% of the time in blind votes. FLUX.2 Klein 4B costs 7.8× less ($0.005 against $0.039 an image), so it wins when “good enough” will do.
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 Nano Banana (Gemini 2.5 Flash Image)
Price per image · 1024×1024, lower is better
Text to image · arena Elo, higher is better
Editing · arena Elo, higher is better
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 Nano Banana (Gemini 2.5 Flash Image) 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
Nano Banana (Gemini 2.5 Flash Image)
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
Nano Banana (Gemini 2.5 Flash Image)
Product shot
“A glass perfume bottle on wet black stone, soft studio lighting, water droplets, high-end product photography”
FLUX.2 Klein 4B
Nano Banana (Gemini 2.5 Flash Image)
Image 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
Nano Banana (Gemini 2.5 Flash Image)
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 $3.90 with Nano Banana (Gemini 2.5 Flash Image)
- you want open weights you can run yourself
Pick Nano Banana (Gemini 2.5 Flash Image) if
- you want the better picture: in blind votes people chose its image over FLUX.2 Klein 4B’s about 70% of the time
- you mostly edit pictures: it scores higher in the editing arena (Elo 984 against 938)
The specs
| Spec | FLUX.2 Klein 4B | Nano Banana (Gemini 2.5 Flash Image) |
|---|---|---|
| Price per image | $0.005 ($0.02 per edit) | $0.039 |
| 100 images | $0.50 | $3.90 |
| Text-to-image Elo | 837 ±12 (#96 in the arena) | 985 ±12 (#59 in the arena) |
| Editing Elo | 938 ±17 (#62 in the arena) | 984 ±14 (#54 in the arena) |
| Arena votes | 6,418 | 5,312 |
| Edits uploaded pictures | Yes | Yes |
| Largest size | — | — |
| Open weights | Yes | No |
| Zero data retention | — | No |
| Lab | Black Forest Labs | |
| Official name | FLUX.2 [klein] 4B | Nano Banana (Gemini 2.5 Flash Image) |
| Released | January 2026 | August 2025 |
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 Nano Banana (Gemini 2.5 Flash Image)?
People picked Nano Banana (Gemini 2.5 Flash Image)’s picture over FLUX.2 Klein 4B’s about 70% of the time in blind votes. FLUX.2 Klein 4B costs 7.8× less ($0.005 against $0.039 an image), so it wins when “good enough” will do.
Which is cheaper, FLUX.2 Klein 4B or Nano Banana (Gemini 2.5 Flash Image)?
FLUX.2 Klein 4B: $0.005 for a 1024×1024 image, against $0.039 for Nano Banana (Gemini 2.5 Flash Image). 100 images cost $0.50 and $3.90.
Can FLUX.2 Klein 4B and Nano Banana (Gemini 2.5 Flash Image) 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 Nano Banana (Gemini 2.5 Flash Image) 984.
How can I compare FLUX.2 Klein 4B and Nano Banana (Gemini 2.5 Flash Image) 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.