Artificial Analysis ranks FLUX 3 Image Klein second among open-weight models for image generation
Written by AI
Black Forest Labs’ open-weight image model FLUX 3 Image Klein scored almost the same Elo as the leading open-weight model, Qwen-Image-2.1, in Artificial Analysis’s blind votes. It trails the best image models overall by a clear margin.
Artificial Analysis (AA) published its assessment of Black Forest Labs’ (BFL) new FLUX 3 image models on its X account on 5 November. FLUX 3 Image Klein is a 5.6-billion-parameter open-weight model that BFL released on 15 October. AA ranks it second among open-weight models in the text-to-image benchmark AA-Image-T2I v2.1 and third in the image editing benchmark AA-Image-Editing v2.1.
In AA’s comparison, human raters see two images generated from the same prompt without knowing which model made each, and pick the one they prefer. The votes produce an Elo score: the more often a model’s image wins, the higher its score. AA tested Klein and FLUX 3 Image through BFL’s API at 1K resolution. The API first expands the prompt into a more detailed one, and only then does the model generate the image. The results therefore apply to images made through the API.
Klein’s gap to the leading open-weight model is within the margin of error
The table shows the FLUX 3 models from AA’s leaderboard, Klein’s predecessor FLUX.2 [klein] 9B, the top three open-weight models and the overall leader.
| Model | Elo | 95% confidence interval | Price / 1,000 images |
|---|---|---|---|
| GPT Image 2.5 Sunburst (max) | 1,227 | 1,217–1,237 | $210.72 |
| FLUX 3 Image | 1,117 | 1,105–1,129 | $48 |
| Qwen-Image-2.1 | 1,044 | 1,032–1,056 | no API |
| FLUX 3 Image Klein | 1,043 | 1,031–1,055 | $9 |
| Fibo 2.0 | 1,040 | 1,028–1,052 | $32 |
| FLUX.2 [klein] 9B | 932 | 922–942 | $15 |
Source: AA-Image-T2I v2.1 leaderboard. Prices on the model developer’s API at 1024×1024 resolution.
Klein trails Qwen-Image-2.1 by one point, and their confidence intervals almost completely overlap. These figures cannot settle the order. Fibo 2.0 also falls within the same range. On the list of all models, Klein ranks 22nd and FLUX 3 Image, released on 1 October, 13th.
Strongest in gaming images, weakest in retail images
AA also compares models across ten use cases. Both FLUX 3 models perform best on animation and gaming images, such as game graphics, concept art and character design. A chart in the post shows Klein 143 Elo points behind the best model in this category.
Compared with its predecessor FLUX.2 [klein] 9B, Klein improved most in UI/UX design: AA said the predecessor sat in the bottom third of that use case’s leaderboard, while Klein is in the top quarter. Retail and e-commerce remains Klein’s weakest use case, AA said. The chart shows Klein 216 points behind the category leader there, but the gap is slightly larger for live-action film images, at 219 points.
Licence, price and availability
BFL released Klein under the FLUX Kommunity License, which allows free non-commercial use. Individuals and companies with annual revenue under $5 million may use the images the model generates commercially.
On BFL’s API, Klein costs $9 per 1,000 1K images, which AA said is 40 per cent less than FLUX.2 [klein] 9B. Klein is available on BFL’s API and in the BFL Playground, and its weights are on Hugging Face. FLUX 3 Image is available on BFL’s API, fal and OpenRouter.
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