# FLUX 3 Image Klein vs FLUX.2 [klein]

> Updated 2026-10-16 · https://imageklein.com/flux-3-image-klein-vs-flux-2-klein

FLUX 3 Image Klein (5.6B, October 2026) replaces the FLUX.2 [klein] models (4B and 9B, January 2026) as Black Forest Labs' small open image model. It adds native 4K, bounding boxes and up to 10 reference images, and BFL measures +91 Elo in text-to-image and +70 Elo in editing over FLUX.2 [klein] 9B — with 38% fewer parameters.

|  | FLUX 3 Image Klein | FLUX.2 [klein] 9B | FLUX.2 [klein] 4B |
|---|---|---|---|
| Released | Oct 15, 2026 | Jan 15, 2026 | Jan 15, 2026 |
| Generator size | 5.6B | 9B | 4B |
| Native 4K | Yes | — | — |
| Bounding boxes | Yes | — | — |
| Reference images | Up to 10 | not documented at the same level |
| Quality (BFL Elo vs 9B) | +91 text-to-image, +70 editing | baseline | — |
| API price | $0.009 (1K) – $0.036 (4K) | $0.015 / image | $0.014 / image |
| License | FLUX Kommunity (free commercial under $5M) | FLUX Non-Commercial | Apache-2.0 |
| Minimum VRAM (BFL) | 8 GB (INT8) | ≈13 GB quoted at launch |

FLUX.2 [klein] figures from BFL's API release notes (January 2026); “—” means the feature wasn't part of that model's documented feature set.

## Should you switch?

- **Yes** for quality, 4K, layout control or multi-image composition — and for commercial use if you're under $5M revenue (9B was non-commercial).
- **Maybe not** if you depend on the Apache-2.0 license of FLUX.2 [klein] 4B (for example, a large company self-hosting), or on existing FLUX.2 LoRAs — they don't carry over to a new architecture.

## FAQ

**Is FLUX 3 Image Klein better than FLUX.2 klein?**
In BFL's blind evaluations, yes: +91 Elo in text-to-image and +70 Elo in image editing over FLUX.2 [klein] 9B, while adding native 4K, bounding boxes and up to 10 reference images.

**Do FLUX.2 klein LoRAs work with FLUX 3 Image Klein?**
No. FLUX 3 Image Klein is a new model; LoRAs need to be retrained on flux-3-image-klein-base.


## Sources

- [Black Forest Labs — FLUX 3 Image Klein (blog, Oct 15, 2026)](https://bfl.ai/blog/flux-3-image-klein)
- [BFL docs — API release notes](https://docs.bfl.ml/release-notes)
- [Hugging Face — black-forest-labs/flux-3-image-klein (model card)](https://huggingface.co/black-forest-labs/flux-3-image-klein)
- [Unite.AI — 5.6B FLUX 3 Image Klein debuts as open-weights release](https://www.unite.ai/new-5-6b-parameter-flux-3-image-klein-debuts-as-open-weights-release/)