Fast
Flux.2 Klein 4B — FLUX on Your iPhone, iPad, and Mac
Flux.2 Klein 4B is the recommended starting point: a four-step FLUX.2 model that runs on every supported device, from an 8 GB iPhone to any Apple Silicon Mac. It supports negative prompts and on-device prompt rewriting, and shares its text encoder with Z-Image-Turbo, so installing both costs less than their combined size.
What Flux.2 Klein 4B Supports
| iPhone | 8 GB |
|---|---|
| iPad | 8 GB |
| Mac | Any Apple Silicon Mac |
| Download size | 4.96 GB (2.53 GB when the shared text encoder is already installed) |
| Steps | 4 (fixed) |
| Negative prompt | Yes |
| Rewrite Prompt (on-device enhancer) | Yes |
| Output sizes | S · M · L everywhere; XL on 16 GB devices |
| Latent upscaler | Off · 1.5x · 2x |
| License | Apache License 2.0. Your images are yours, including for commercial use. |