Fly.io
Harbor
| Feature | Fly.io | Harbor |
|---|---|---|
| Pricing | Free / from $0/mo | Free only |
| Free Plan | ✓ Yes | ✓ Yes |
| Rating | 4.2 / 5 | 4.3 / 5 |
| Best For | full-stack-developers, global-apps, edge-computing, hobby-projects | enterprise-devops, container-teams, security-teams, regulated-industries |
| Founded | 2017 | 2016 |
| Global Deployment | ✓ | ✗ |
| Firecracker Vms | ✓ | ✗ |
| Fly Postgres | ✓ | ✗ |
| Auto Scaling | ✓ | ✗ |
| Volumes | ✓ | ✗ |
| Private Networking | ✓ | ✗ |
| Gpu Support | ✓ | ✗ |
| Container Registry | ✗ | ✓ |
| Vulnerability Scanning | ✗ | ✓ |
| Rbac | ✗ | ✓ |
| Image Signing | ✗ | ✓ |
| Replication | ✗ | ✓ |
| Garbage Collection | ✗ | ✓ |
| Audit Logs | ✗ | ✓ |
✓ Fly.io Pros
- Deploy apps globally to 30+ regions easily
- Built-in Postgres and Redis for data at the edge
- Generous free tier for hobby projects
- Firecracker VMs start in milliseconds
✗ Fly.io Cons
- Operational complexity for simple apps
- Documentation can be hard to navigate
- Billing surprises if auto-scaling triggers unexpectedly
✓ Harbor Pros
- Completely free and CNCF graduated project
- Built-in vulnerability scanning (Trivy integration)
- Image signing and policy enforcement
- Multi-registry replication for geo-distribution
✗ Harbor Cons
- Requires self-hosting and infrastructure management
- UI is functional but not modern
- Initial setup complexity for production
The Verdict
Fly.io is built for full stack developers and global apps, with a focus on global-deployment and firecracker-vms. Harbor targets enterprise devops and container teams and leads with container-registry and vulnerability-scanning.
Harbor uses custom enterprise pricing, while Fly.io starts at $0/mo — a tangible advantage for teams with a fixed budget.
Both offer free plans, so you can test each with your real workflow before committing to a subscription.
This is a genuinely close comparison. If you can, sign up for both free trials (where available) and run a one-week test with your actual team tasks before deciding.