FLUX.2-Klein-4B

FLUX.2 Klein generates images from a text prompt and, when given multiple reference images, produces new compositions that preserve the exact identity of the subject in those references — a face, a product, a brand mark — across every generation.

On AutorunX it's the default model for Banner Ad creative and for exact-identity persona generation, the two jobs where its combination of low cost, fast turnaround, and multi-reference identity locking matters most.

FLUX.2 Klein 4B is the compact entry point of Black Forest Labs' FLUX.2 model family, purpose-built for minimal latency rather than maximum scale. A single 4-billion-parameter checkpoint handles text-to-image generation, image editing, and multi-reference generation, instead of shipping separate models for each mode.

Its small footprint is the point: Klein 4B fits comfortably within a modest VRAM budget, which is exactly why AutorunX runs it in-house — as AX-KLN — on its own RunPod GPU fleet's 16GB VRAM lane instead of renting it from a third-party API. That ownership is what lets AutorunX offer it at close to the platform's lowest possible credit cost.

Multi-reference generation lets Klein take several input images (for instance, angles of the same person or product) and produce new outputs that stay exact-identity consistent with them, which is why AutorunX defaults to it for AI Influencer persona work where a generated character has to look like the same person across every shot.