Research note
Research note: Black Forest Labs releases FLUX 3 Image Klein, a 5.6-billion-parameter open image model that runs on 8 GB graphics cards
How we checked FLUX 3 Image Klein’s size, licence and speed claims against Black Forest Labs’ post and model card.
What we set out to check
What Black Forest Labs released, who can use it for free, how fast it is and which claims are the company’s own.
What we found
- The blog and model card agree on the 5.6B size and the $5 million revenue threshold.
- Speed figures come from the company and mix on-GPU times with API latency.
- The model card adds that short prompts give generic output without the upsampler.
Numbers that differ
The model card lists 6B in its metadata, which includes the separate text encoder. We use 5.6B for the image model, as both sources describe it.
Labels we chose and why
- Confirmed for release, size and licence.
- Company claim for speed and ranking.
What we could not verify
- Independent quality comparisons.
- The full API price table.
What we searched
- FLUX 3 Image Klein
- FLUX Kommunity License revenue
- FLUX 3 Klein RTX 5090 speed
Every source we read
| Source | Used? | Why |
|---|---|---|
| Black Forest Labs blog | USED | Release, licence summary, speed figures and comparisons. |
| Hugging Face model card | USED | Licence name, usage notes and the prompt-upsampler advice. |
| AI Weekly | NOT USED | Short summary. |