FLUX.1 Dev is the open-weights centerpiece of the original Flux generation: a 12-billion-parameter, guidance-distilled model that delivered near-Pro quality in a checkpoint anyone could download. It became one of the most-downloaded image models on Hugging Face and the substrate for an entire economy of LoRAs, fine-tunes, and ControlNet-style tooling — when people say they “trained a Flux LoRA”, this is almost always the base they mean.
Dev shipped under Black Forest Labs’ non-commercial license: free for research, education, and personal work, with commercial output requiring a paid arrangement. That split — open enough to build a community, restricted enough to protect the API business — became BFL’s template, carried forward into the Flux 2 generation where Dev now has a direct successor in Flux 2 Dev alongside the Apache-licensed Klein.
The classic still runs in thousands of local pipelines, but the frontier has moved. For today’s Flux quality without a GPU, a license question, or a ComfyUI graph, Flux 2 Pro is hosted on Flux 3 AI — generating in the browser on free starter credits, with Flux Kontext beside it for the instruction-based editing the FLUX.1 era never had.
See what's possible on Flux 3 AI
Sample generations from the platform — write your own prompt to see what Flux 1 Dev does with it.
What makes Flux 1 Dev stand out
12B open weights
A full-scale checkpoint at near-Pro quality — the download that defined open AI imaging for a generation.
The LoRA standard
The vast majority of the Flux fine-tune and LoRA ecosystem is built on the FLUX.1 Dev base.
Guidance-distilled
Distillation gave Dev efficient sampling while preserving the quality of its Pro-class teacher.
Non-commercial license
Free for research and personal projects; commercial output needs licensing from BFL.
A living lineage
Flux 2 Dev and Klein carry the open-weights torch; hosted Flux 2 Pro carries the quality crown.
Popular use cases
Why creators run Flux 1 Dev on Flux 3 AI
- Current-generation Flux quality with zero setup — no checkpoints, graphs, or VRAM budgeting.
- Commercial clarity: hosted renders are covered by platform terms, not weights licenses.
- Your credit balance also unlocks Kontext editing and the full video catalog — Veo, Sora 2, Kling.
Flux 1 Dev specs & capabilities
Output
- Generation modesText to Image
Flux 1 Dev prompt examples
Copy one as a starting point, or send it straight to the Create studio.
“Fantasy character portrait of a silver-haired ranger in a rain-soaked forest, intricate leather armor detail, cinematic rim light, painterly realism”
The character-art genre where Dev LoRAs flourished — try it on the flagship
“Watercolor illustration of a lighthouse on a stormy cliff, loose washes, visible paper texture, limited indigo palette”
Style-transfer territory that Dev fine-tunes made their own
“Photoreal studio portrait of a jazz musician with a trumpet, dramatic Rembrandt lighting, smoke haze, deep black background”
The near-Pro realism that earned Dev its reputation, on today’s generation
Create with Flux 1 Dev in three steps
Describe your idea
Write a prompt — the more specific the scene, motion, and style, the better Flux 1 Dev performs.
Pick Flux 1 Dev & settings
Choose your aspect ratio and options. The studio shows the exact credit cost before you generate.
Generate & download
Flux 1 Dev renders in the cloud — track progress in your library, then download watermark-free or share with a link.
Flux 1 Dev questions, answered
What is FLUX.1 Dev?
FLUX.1 Dev is Black Forest Labs’ original open-weights Flux model — a 12-billion-parameter, guidance-distilled text-to-image network that became the standard base for Flux fine-tunes and one of the most popular open image models ever released.
Can I use FLUX.1 Dev images commercially?
Not under the default weights license — Dev is non-commercial, covering research, education, and personal use, with commercial rights sold separately by BFL. Hosted generation on Flux 3 AI avoids the question: platform renders are cleared for commercial use under the platform terms.
Why is FLUX.1 Dev so popular for LoRAs?
It hit the sweet spot: full-size quality, downloadable weights, and enormous community tooling. Style LoRAs, character LoRAs, and control adapters standardized on the Dev base, creating a network effect that kept it central long after newer models appeared.
FLUX.1 Dev vs Flux 2 — should I still use the classic?
If your workflow depends on a specific Dev-based LoRA or fine-tune, the classic remains useful. For raw generation quality, the Flux 2 generation is a clear step up — locally through Flux 2 Dev or Klein, hosted through Flux 2 Pro on this platform.
What hardware does FLUX.1 Dev need locally?
The full checkpoint favors GPUs in the 16GB+ VRAM class, with quantized community builds squeezing onto smaller cards at some quality cost. The zero-hardware alternative is hosted Flux 2 Pro, which renders in the cloud from any browser.
Is FLUX.1 Dev available on Flux 3 AI?
No — Dev belongs to local pipelines. This page’s Generate button opens the Create studio with Flux 2 Pro, the current hosted flagship of the same family, running on your free starter credits with watermark-free downloads.