Unofficial guide. Not affiliated with Meta, Black Forest Labs or fal.
Last verified: 21 October 2026
Two of October 2026’s open-weight releases could hardly sit further apart in hardware terms. Muse Spark Open (released 15 October 2026) is an 816B-total / 42B-active MoE with a 1M-token context whose checkpoints need roughly 1,600GB (BF16) or 530GB (NVFP4) of memory. FLUX 3 Image Klein (also 15 October 2026) is a 5.6B-parameter image model whose INT8 build runs in 8GB of VRAM. Enter your machine’s memory below and get a straight verdict for each.
The checker
Muse Spark Open
FLUX 3 Image Klein
Why Spark Open is a hosted model for almost everyone
The weights are free to download from Hugging Face (meta-models/Muse-Spark-Open-816B-A42B), under the Muse Model License – free is not the problem; memory is. Even the smaller NVFP4 checkpoint needs about 530GB. Tellingly, when Meta and Apple demoed local running, they used two 512GB M5 Ultra Mac Studios – machines that are not yet shipping. For everyone else, a hosted API is the realistic route. Where to get the weights and what the routes are: Muse Spark Open Download: Where to Get It and How People Run It.
Why Klein is the opposite
FLUX 3 Image Klein is a 5.6B-parameter image model. Its INT8 build runs on 8GB of VRAM in ComfyUI and Diffusers, which puts it within reach of an ordinary gaming PC. Its weights sit under the FLUX Kommunity License – free commercial use only under $5M annual revenue. Model background: the Spark Open section of What Is Muse Wonder? and FLUX 3 Max Explained for the FLUX family.
Last verified: 21 October 2026
Unofficial guide. Not affiliated with Meta, Black Forest Labs or fal.
Free alternatives, honestly labelled
Both models on this page sit next to paid flagships. What is genuinely free – and what each free thing is not – is collected in Free Alternatives to Muse Wonder, Gemini 4 Argon and FLUX 3 Max.