Fly.io Review 2026: Global App Deployment
Fly.io runs your apps as micro VMs in 30+ regions worldwide. Your app literally runs close to your users. After deploying three services on Fly.io, here's the honest review.
What Fly.io Does
- Global deployment — run VMs in 30+ regions
- Docker-based — deploy any Docker image
- Fly Machines — fast-starting micro VMs
- Fly Postgres — managed Postgres with replicas
- Private networking — WireGuard-based internal network
- Auto-scaling — scale to zero or scale up based on traffic
- Volumes — persistent storage for stateful apps
What I Like
True Global Deployment
Deploy to iad (Virginia) and cdg (Paris) and nrt (Tokyo) simultaneously. Users connect to the nearest region. Latency drops from 200ms to 30ms for global users.
fly regions add iad cdg nrt sin
fly deploy
Your app now runs on four continents. Nothing else does this as simply.
Fly Machines
Micro VMs that start in ~300ms. Not containers — actual VMs with their own kernel. More isolated and secure than containers. Scale to zero when idle.
Generous Free Tier
- 3 shared VMs (256MB RAM each)
- 3GB persistent storage
- 160GB outbound bandwidth
Enough to run a small app for free indefinitely.
WebSocket Support
First-class WebSocket and long-lived connection support. Many platforms (Vercel, Cloudflare Workers) struggle with WebSockets. Fly.io handles them natively.
Postgres with Read Replicas
Deploy Postgres in your primary region. Add read replicas in other regions. Global apps with fast database reads everywhere.
Fly CLI
The flyctl CLI is excellent. Deploy, scale, SSH into VMs, check logs, manage secrets — all from the terminal. Great DX for CLI-oriented developers.
What I Don't Like
Steeper Learning Curve
Fly.io is more complex than Railway or Render. You configure fly.toml, manage machines, handle volumes. It's closer to managing servers than a true PaaS.
Unreliable Deploys (Historically)
Fly.io has had periods of instability. Deployments sometimes hang, machines don't start, or health checks fail intermittently. It's improved significantly but not as reliable as Railway or Render.
Documentation Gaps
Docs are good but have gaps. Some features are documented in blog posts or community forums rather than official docs. You'll spend time googling.
Postgres Isn't Fully Managed
Fly Postgres is "managed" but you're responsible for backups, failover, and maintenance. It's not as hands-off as Supabase or Neon. For production, consider using a dedicated database service.
Pricing Complexity
Usage-based with compute, memory, bandwidth, and storage all priced separately. Estimating your bill requires a spreadsheet.
Pricing
| Resource | Free | Paid |
|---|---|---|
| Shared VMs | 3 free | $1.94/mo per VM (256MB) |
| Dedicated VMs | - | $0.0070/sec per CPU |
| Memory | 256MB per free VM | $0.0000020/sec per MB |
| Volumes | 3GB | $0.15/GB/mo |
| Bandwidth | 160GB | $0.02/GB |
Typical costs:
- Hobby app: $0 (free tier)
- Small API: $5-15/month
- Global API (3 regions): $20-50/month
Best Use Cases
- Global apps — deploy close to users worldwide
- WebSocket apps — chat, gaming, real-time collaboration
- Docker-based services — run any Docker image
- Multi-region databases — Postgres with read replicas
- Scale-to-zero — pay nothing when idle
Worst Use Cases
- Simple web apps — Railway or Render is simpler
- Static sites — use Vercel or Cloudflare Pages
- Hands-off hosting — Fly requires more operational knowledge
- Teams wanting a dashboard — CLI-first experience
FAQ
Is Fly.io production-ready?
Yes, with caveats. Use health checks, add monitoring, and have a rollback plan. Fly has improved stability significantly but isn't as bullet-proof as AWS.
Fly.io vs Railway?
Railway is simpler (dashboard-first, one-click databases). Fly.io is more powerful (multi-region, WebSockets, VMs). Choose Railway for simplicity, Fly for global deployment.
Can I run Next.js on Fly.io?
Yes. Dockerfile-based deployment. Works well but Vercel is simpler for Next.js specifically.
Is the free tier really free?
Yes. 3 VMs with 256MB RAM each. No credit card required. Enough for hobby projects.
Bottom Line
Fly.io is the best platform for deploying apps globally in 2026. Multi-region deployment, WebSocket support, and scale-to-zero make it unique. The tradeoff is complexity — it's more work than Railway or Render. Worth it when you need global presence or long-lived connections.
Recommendation: Use Fly.io for apps that need multi-region deployment or WebSocket support. Use Railway for everything else.