black-forest-labs · image

FLUX.2-dev

black-forest-labs/FLUX.2-dev

FLUX.2-dev at Q4_K_M is exactly 19,959,731,168 bytes (18.59 GiB / 19.96 GB) — an effective 4.955 bits per weight, not the nominal 4.

From the file· summed from 1 file(s)
Parameters
32.2B
Architecture
flux
Context
native (config.json)
License
other

Shipped quantizations

exact bytes, summed from published files
QuantSizeExact bytesEffective bpwTensorsPublisher
Q2_K11.98 GiB12,858,250,2083.192unsloth
Q2_K11.98 GiB12,858,250,2083.192city96
Q3_K_S14.55 GiB15,628,063,7123.880gguf-org
Q3_K_S14.57 GiB15,649,297,3763.885unsloth
Q3_K_S14.70 GiB15,779,648,4803.918city96
Q3_K_L14.74 GiB15,829,783,5203.930unsloth
Q3_K_M14.74 GiB15,829,783,5203.930299unsloth
Q3_K_M14.78 GiB15,868,711,9043.940gguf-org
Q3_K_M14.86 GiB15,960,134,6243.962city96
Q3_K_L14.99 GiB16,095,204,3203.996gguf-org
Q4_017.97 GiB19,299,128,2884.791299unsloth
Q4_017.97 GiB19,299,128,2884.791city96
Q4_K_S17.97 GiB19,299,128,2884.791city96
Q4_K_S18.43 GiB19,789,861,8564.913unsloth
Q4_K_S18.44 GiB19,799,299,0404.915gguf-org
IQ4_NL18.44 GiB19,799,299,0404.915gguf-org
Q4_K_M18.59 GiB19,959,731,1684.955299unsloth
Q4_K_M18.65 GiB20,025,791,4564.972gguf-org
Q4_K_M18.70 GiB20,082,414,5604.986city96
Q2_K2 shards18.79 GiB20,170,404,5125.008gguf-org
Q4_119.80 GiB21,262,062,5605.279unsloth
Q4_119.80 GiB21,262,062,5605.279city96
Q4_120.27 GiB21,762,233,3125.403gguf-org
Q5_021.63 GiB23,224,996,8325.766unsloth
Q5_K_S21.63 GiB23,224,996,8325.766city96
Q5_021.63 GiB23,224,996,8325.766city96
Q5_K_S22.10 GiB23,725,167,5845.890gguf-org
Q5_022.10 GiB23,725,167,5845.890gguf-org
Q5_K_S22.12 GiB23,746,401,2485.896unsloth
Q5_K_M22.28 GiB23,926,887,3925.940299unsloth
Q5_K_M22.32 GiB23,965,815,7765.950gguf-org
Q5_K_M22.41 GiB24,057,238,4965.973city96
Q5_123.46 GiB25,187,931,1046.253unsloth
Q5_123.46 GiB25,187,931,1046.253city96
Q5_123.92 GiB25,688,101,8566.378gguf-org
Q6_K25.51 GiB27,396,232,1606.802299unsloth
Q6_K25.51 GiB27,396,232,1606.802city96
Q6_K25.98 GiB27,896,402,9126.926gguf-org
IQ4_XS2 shards27.88 GiB29,936,513,6967.432gguf-org
Q4_02 shards29.28 GiB31,438,992,0327.805gguf-org

Pipeline components

a diffusion model is a graph of parts, not one file
ComponentSizeShareCan live on the CPU?
denoiser60.33 GiB57%no, must be resident
text encoder44.72 GiB42%yes — the usual first VRAM saving
vae0.31 GiB0%no, must be resident
Full pipeline105.37 GiBresident if nothing is offloaded

The parameter count published for a diffusion model describes the denoiser alone. Running it also requires its text encoder and VAE, and the text encoder is often nearly as large as the denoiser — which is why offloading it is the standard first move when you run out of memory. This repository also ships a single-file copy of the denoiser at its root; we count it once, not twice.

We publish component sizes here, not throughput. Community-submitted image-generation rates do exist for many GPUs and we show them on the hardware pages, but they aggregate runs at different resolutions, step counts and settings, so they cannot be attributed to one model. Peak memory during sampling is unmeasured by any public source, and we do not estimate it.

Compare with

same modality, comparable size

Will it run on your card?

full quant x context sweep

Why other calculators give a different number

A parameters × bits ÷ 8 estimate puts Q4_K_M at roughly 16.88 GiB. The real file is 18.59 GiB, because a quantization is a mixture and some tensors are always kept at higher precision.

Architecture

Architecture unavailable — this repository is gated and no ungated mirror was found. Exact file sizes above are still authoritative; only the KV math needs the config.

Questions people ask

How much VRAM does FLUX.2-dev need?
Q4_K_M is exactly 19,959,731,168 bytes (18.59 GiB) in weights. Add the KV cache, which depends on your context length, plus roughly half a gigabyte of runtime overhead.
Which quantization of FLUX.2-dev should I use?
Q4_K_M is the usual default. Pick the largest quantization that fits your card at the context you actually need — the table above gives exact sizes for every one published.