Will It Run AI
black forest labs

Flux.1 Dev

Frontier

by Black Forest Labs

State-of-the-art text-to-image model from Black Forest Labs. Excels at photorealism, text rendering, and prompt adherence. 12B parameter DiT architecture with dual text encoders: T5-XXL (4.7B) and CLIP-L (0.12B).

VRAM requirements, GPU fit, and setup notes for Flux.1 Dev, including 8GB/12GB fit guidance where relevant. Recommended runtimes: ComfyUI and Diffusers support. Best download size: ~6.8 GB at Q4_0.

  • Best-in-class text rendering in images
  • Excellent prompt adherence
  • 12B DiT architecture with flow matching
  • Requires T5-XXL (4.7B) + CLIP-L text encoders
ComfyUI, DiffusersQ2_K safetensors

Your hardware

Detecting...

Parameters12B
Max Resolution1024×1024
Default Steps28
ArchitectureDIT
Licenseflux-1-dev-non-commercial

Image Quality Benchmarks

Measured quality metrics for Flux.1 Dev outputs.

Human Preference Score95%

How often humans prefer this model's output (0-100%)

Aesthetic Score8.2

Visual quality and composition rating (5-9 scale)

CLIP Score0.32

Text-image alignment accuracy (higher is better)

VRAM Requirements by Resolution and Precision

Compare which GPUs can run Flux.1 Dev at different precisions. FP8 uses less memory than FP16 when available, and the grade shows how comfortably each GPU handles the workload.

FP16 (full precision)

ResolutionVRAM RequiredRTX 4090 24GBRTX 3060 12GBRTX 4060 8GBMacBook Pro M4 Pro 24GB
512×51223.6 GBBFFF
768×76823.8 GBBFFF
1024×102424.0 GBBFFF

FP8 (~40% less VRAM)

ResolutionVRAM RequiredRTX 4090 24GBRTX 3060 12GBRTX 4060 8GBMacBook Pro M4 Pro 24GB
512×51212.6 GBSBFS
768×76812.8 GBSBFS
1024×102413.0 GBSBFS

Q8_0

ResolutionVRAM RequiredRTX 4090 24GBRTX 3060 12GBRTX 4060 8GBMacBook Pro M4 Pro 24GB
512×51212.6 GBSBFS
768×76812.8 GBSBFS
1024×102413.0 GBSBFS

Q5_K_S

ResolutionVRAM RequiredRTX 4090 24GBRTX 3060 12GBRTX 4060 8GBMacBook Pro M4 Pro 24GB
512×51213.8 GBSDFA
768×76814.1 GBSDFA
1024×102414.5 GBSDFA

Q4_0

ResolutionVRAM RequiredRTX 4090 24GBRTX 3060 12GBRTX 4060 8GBMacBook Pro M4 Pro 24GB
512×5126.7 GBSSAS
768×7686.8 GBSSAS
1024×10247.0 GBSSAS

Optimization Tips

GGUF Q4 available

Quantized GGUF format for lower VRAM and smaller downloads -- reduces download from 23.8 GB to 6.8 GB

Turbo / LCM distillation

Use distilled scheduler at 4-8 steps for faster iteration

ControlNets available

Add guided generation with 3 adapters (+3.6 GB VRAM each)

Run with Python

Run with Python (diffusers)
from diffusers import FluxPipeline
import torch

pipe = FluxPipeline.from_pretrained(
    "black-forest-labs/FLUX.1-dev",
    torch_dtype=torch.float16
)
pipe.to("cuda")

image = pipe(
    prompt="your prompt here",
    num_inference_steps=28,
    guidance_scale=3.5,
    height=1024,
    width=1024,
).images[0]
image.save("output.png")

Get started

Setup instructions for running Flux.1 Dev locally

1. Download the model

Get the checkpoint from HuggingFace

2. Place in:

ComfyUI/models/checkpoints/ (or ComfyUI/models/unet/ for GGUF)

3. Launch ComfyUI

python main.py

ComfyUI Workflow

Basic txt2img workflow for Flux.1 Dev

8 nodes

Drag & drop into ComfyUI or use File → Import

Memory Breakdown

VRAM allocation at 1024×1024 on RTX 4090 24GB (24 GB)

Required: 24.0 GBAvailable: 24.0 GB
Weights24.0 GB
VAE0.2 GB
Text Encoder9.6 GB
Activations0.8 GB
Overhead0.5 GB

Estimated Generation Time

Time per image at 1024×1024, 28 steps, FP16.

RTX 4090 24GB~18s
RTX 3060 12GB~1m 8s
RTX 4060 8GB~1m 42s
MacBook Pro M4 Pro 24GB~2m 26s

Sample Outputs

Available Formats, Downloads & Setup

Download Flux.1 Dev in the precision that matches your GPU. Lower precision usually means less VRAM pressure, while higher precision keeps more quality.

FormatoPrecisiónTamañoProveedor
Pesos oficiales
safetensorsRecomendadoFP1623.8 GBofficialDescargar
safetensorsFP811.9 GBofficialDescargar
Conversiones de la comunidad
ggufComunidadQ2_K4.0 GBcommunity-ggufDescargar
ggufComunidadQ3_K_S5.2 GBcommunity-ggufDescargar
ggufComunidadQ4_06.8 GBcommunity-ggufDescargar
ggufComunidadQ4_K_S6.8 GBcommunity-ggufDescargar
ggufComunidadQ5_08.3 GBcommunity-ggufDescargar
ggufComunidadQ5_K_S8.3 GBcommunity-ggufDescargar
ggufComunidadQ6_K9.9 GBcommunity-ggufDescargar
ggufComunidadQ8_012.7 GBcommunity-ggufDescargar

ControlNet Support

3 ControlNets available for Flux.1 Dev. ControlNets add guided image generation (edges, depth, pose) at the cost of extra VRAM.

Canny Edge

+3.6 GB VRAM

Extract edges from reference image to guide composition and structure. Best for architectural and product photography.

comfyuidiffusers
View on HF

Depth Map

+3.6 GB VRAM

Use depth estimation to maintain 3D spatial relationships. Great for scenes with foreground/background separation.

comfyuidiffusers
View on HF

Union (Multi-Control)

+3.6 GB VRAM

Single model that handles canny, depth, pose, tile, and blur conditions. Most versatile option for Flux.

comfyuidiffusers
View on HF

LoRA Ecosystem

Growing Ecosystem

Growing ecosystem with hundreds of LoRAs on CivitAI and HuggingFace. Flux LoRAs are typically smaller than SDXL LoRAs due to the DiT architecture.

Approximately 500 LoRAs available on CivitAI. Each LoRA adds ~0.3 GB VRAM.

Popular LoRAs for Flux.1 Dev

NameCategoryDownloads
Flux Realism LoRAstyle200KView
Flux Animestyle150KView
Browse all LoRAs on CivitAI

Related Workflows

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Frequently asked questions

FAQ — Flux.1 Dev VRAM, Runtimes & Fit

How much VRAM does Flux.1 Dev need?

Flux.1 Dev (12B parameters) requires approximately 24.0 GB of VRAM at FP16 precision for standard 1024×1024 image generation. If you want a lighter setup, lower precisions like FP8 can reduce memory use when available.

Can I run Flux.1 Dev on an 8GB GPU?

Yes, Flux.1 Dev can fit on some 8GB GPUs at ~6.8 GB at Q4_0. Check the VRAM table above for the exact resolution and precision trade-off.

Does Flux.1 Dev work in ComfyUI and Diffusers?

Flux.1 Dev is marked for ComfyUI and Diffusers support in our catalog, so those are the runtimes we recommend first for local setup. If your workflow uses another front end, check the model's available formats and workflow notes above before downloading.

Can I run Flux.1 Dev on RTX 4090?

Flux.1 Dev can run on the RTX 4090 with sequential offloading enabled, though generation will be slower than native fit.

Does Flux.1 Dev support ControlNet?

Yes, Flux.1 Dev has 3 ControlNet adapters available: Canny Edge, Depth Map, Union (Multi-Control). Each ControlNet adds roughly 3.6 GB of extra VRAM.

Does Flux.1 Dev have LoRA support?

Growing ecosystem with hundreds of LoRAs on CivitAI and HuggingFace. Flux LoRAs are typically smaller than SDXL LoRAs due to the DiT architecture. The LoRA ecosystem for Flux.1 Dev is rated as "moderate". There are approximately 500 LoRAs available on Civitai. Each LoRA adds roughly 0.3 GB of extra VRAM.

How fast is Flux.1 Dev?

On a reference GPU (RTX 4090 24GB), Flux.1 Dev generates a 1024×1024 image in approximately ~18s at FP16 with 28 inference steps. Faster GPUs with higher memory bandwidth will produce images more quickly.

About Flux.1 Dev

Use cases
photorealisticartdesigntext-rendering
Recommended runtimes
comfyuidiffusers

See also