RunPod and Vast.ai are the two most-recommended cheap-GPU options for ML training in 2026. They look similar from the outside — both rent GPUs by the hour from a mix of datacenter and community hosts — but they differ enough that picking the wrong one wastes time.
Short version: RunPod for sanity; Vast.ai for price. Long version below.
What they have in common
- Hourly billing, no minimum commit.
- Linux-only on community instances (Windows is unrealistic on either).
- Pre-built ML images (PyTorch, TensorFlow, JupyterLab).
- SSH access included.
- Range of cards from Tesla T4 to H100.
Where they differ
| RunPod | Vast.ai | |
|---|---|---|
| Pricing model | Fixed list price per GPU type | Bidding marketplace |
| RTX 4090 hourly price | ~$0.34/hr (community) | ~$0.20/hr "interruptible" |
| UI complexity | Clean, opinionated | Dense, filter-heavy |
| Reliability | Predictable | Variable (depends on host) |
| Tier separation | Secure / Community split | Verified / Unverified hosts |
| Per-second billing | Yes | Per-hour |
| Spot interruption risk | Low (only Community) | Higher (host can take machine offline) |
| Affiliate cookie | Yes | 3% lifetime |
When to pick RunPod
- You're training a model that's expensive to restart (long warmup, large dataset loading).
- You want to come back tomorrow to the same instance without checking if a host took it offline.
- You're new to GPU cloud and want a sane UI.
- Your job is multi-hour and you want predictable cost.
When to pick Vast.ai
- You're running a job you can restart easily if it dies.
- The price difference (40–50% cheaper) matters more than reliability.
- You have a specific niche GPU requirement (e.g., very large VRAM) and Vast.ai's marketplace shows availability that RunPod doesn't.
- You're doing batch backtests where interruption just means re-running a fraction.
My honest recommendation
Start with RunPod. The UX wins for the first few training runs are worth the slight price premium. Once you know exactly what you're doing — what card you want, what reliability tier, how to recover from an interrupted job — Vast.ai becomes worth its lower price. Many of us end up using both for different jobs.