Vast.ai
The cheapest GPU cloud marketplace for AI workloads
Founded
2018
Starting Price
From $30.20
Category
AI Image Generation
Last updated April 26, 2026
About Vast.ai
Vast.ai is a peer-to-peer GPU rental marketplace where individual hosts rent out their idle GPUs at deeply discounted rates. It's widely considered the cheapest way to access high-end NVIDIA GPUs (RTX 4090, A100, H100) for Stable Diffusion, ComfyUI, model training, and inference workloads. Renters bid on instances via on-demand or interruptible pricing, with full SSH/Docker access to ComfyUI and Automatic1111 templates.
Pros & Cons
Pros
- By far the cheapest way to rent RTX 4090s and A100s for ComfyUI and Stable Diffusion experimentation
- Wide selection of consumer GPUs (3090/4090) that other clouds rarely offer
- Per-second billing and instant boot make tinkering on a budget realistic
- Pre-built ComfyUI and Automatic1111 templates get you generating in under 5 minutes
- Independent storage volumes let you persist large model libraries cheaply
Key Features
Marketplace Pricing
Hosts compete on price, driving GPU costs down to a fraction of major clouds.
On-Demand & Interruptible
Choose stable on-demand pricing or bid for interruptible instances at up to 50% extra savings.
Docker & Templates
One-click Docker templates for Stable Diffusion WebUI, ComfyUI, Jupyter, and PyTorch.
Wide GPU Selection
RTX 3090, 4090, A100, H100, H200 and more, often available globally.
Per-Second Billing
Granular billing with no minimum commitment.
DLPerf Benchmarks
Built-in performance scoring helps you compare hosts on real ML workloads, not just specs.
SSH & Jupyter Access
Full root access via SSH, web terminal, or Jupyter for custom ComfyUI nodes and extensions.
Pricing
Interruptible
From $30.20/hour
- Bid-based pricing
- Up to 50% cheaper than on-demand
- May be preempted by higher bids
- Best for fault-tolerant workloads
On-Demand
Best For
ComfyUI Tinkering on a Budget
Hobbyists spin up an RTX 4090 for $0.20-0.35/hr to run heavy ComfyUI workflows without buying hardware.
LoRA & Dreambooth Training
Affordable A100/H100 access for fine-tuning Stable Diffusion checkpoints and LoRAs overnight.
Batch Image Generation
Render thousands of SDXL or Flux images in a few hours at marketplace pricing.
Model Benchmarking
Test inference performance across different GPU SKUs before committing to a production host.
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Choose Vast.ai when raw price-per-GPU-hour is the deciding factor — hobbyist ComfyUI, batch image generation, fault-tolerant fine-tuning, and benchmarking before committing to a production host.
