FLUX

Flux is a family of image generation and editing models built by Black Forest Labs. It spans several variants aimed at different needs, from top-quality API models to open-weight versions you can run yourself.

The current generation is FLUX.2, which launched in late 2025 and replaced the older FLUX.1 line. The lineup now includes FLUX.2 [pro], [flex], [max], [dev] and, since January 2026, the compact [klein] model (offered in 4B and 9B sizes). Klein handles both generation and editing, runs on consumer GPUs with around 13GB of VRAM, and delivers sub-second inference; NVIDIA and ComfyUI FP8 optimizations cut VRAM use by roughly 40%.

On capabilities, FLUX.2 supports multi-reference input (up to about 10 reference images) for character and style consistency, photorealistic output up to 4 megapixels, a context window of around 32k tokens, and strong text rendering that reaches roughly 92% accuracy on complex layouts.

Pricing is pay-as-you-go and billed per megapixel, with no subscriptions or seats. FLUX.2 [pro] costs $0.03 for the first megapixel then $0.015 per additional MP (reference images $0.015/MP); [max] is around $0.07 first MP then ~$0.03/MP; [klein] is about $0.014 first MP then ~$0.001/MP. Legacy FLUX.1 [pro] tiers ran roughly $0.04-0.06/MP.

The open-weight side is where the free option lives. FLUX.1 [schnell] is Apache 2.0 and fine for commercial use; FLUX.1 [dev] is non-commercial; FLUX.2 [dev] and [klein] ship with open weights. Commercial self-hosting above certain volumes requires a paid Open Weights license (Builder up to 10K img/mo, Platform/Professional up to 100K, Enterprise custom).

Flux suits developers and studios who want either the best possible photorealism through an API or a self-hostable model they can fine-tune and control, and who are comfortable with per-megapixel billing or license management.