AI-Toolkit (Ostris)
Modern training framework — Flux, SDXL, SD3 LoRAs in YAML.
Open Source 16–24 GB VRAM
- Min VRAM
- 16 GB
- GPU class
- High-end GPU
- Quant
- BF16
Actually FreeNo SignupOpen SourceWatermark-Free
FluxGym
Dead-simple Flux LoRA training in a Gradio UI.
Open Source 12–20 GB VRAMRuns locally
Actually FreeNo SignupOpen SourceWatermark-FreeHobbyist-Friendly
Visit FluxGymUpdated 2026-04-05 · Direct link
Hardware requirements
Runs locally · Mid GPU (12 GB)
Min VRAM
12 GB
Rec. VRAM
20 GB
Min RAM
32 GB
Rec. RAM
64 GB
Disk
40 GB
GPU class
Mid GPU
12.1+Apple Silicon ✓GPU RequiredQuant: FP8
12 GB preset is genuinely usable, just slow; 20 GB is the comfortable spot.
Screenshot placeholder · FluxGym
What is FluxGym?
FluxGym is the friendly face of Flux LoRA training. Web UI on top of Kohya's scripts and AI-Toolkit; drag-drop images, name your concept, hit train. The easiest path from 'I have 15 photos of my dog' to a working Flux LoRA.
Pros & cons
Pros
- Genuinely one-click: install, drop images, train
- Three VRAM presets (12 GB / 16 GB / 20 GB) tuned out of the box
- Active updates following the Flux model ecosystem
Cons
- Less control than AI-Toolkit or raw Kohya
- Locked to Flux — no SDXL / SD3 training
What's actually free?
Apache 2.0.
✓ Actually FreeNo SignupOpen SourceWatermark-Free
Alternatives
Kohya_ss
The standard SDXL/Flux LoRA training UI.
Open Source 12–24 GB VRAM
- Min VRAM
- 12 GB
- GPU class
- High-end GPU
- Quant
- FP16
Actually FreeNo SignupOpen SourceWatermark-Free