Fly.io is a modern cloud platform built for running full-stack applications at the edge. Instead of deploying to a single region, Fly.io distributes your application across 30+ regions worldwide using lightweight Firecracker VMs — the same technology AWS uses for Lambda. This means every user connects to the nearest instance, dramatically reducing latency. Founded in 2017, Fly.io appeals to developers building latency-sensitive applications like real-time collaboration tools, multiplayer games, and global SaaS products. Deployment is Docker-based with a powerful CLI tool (flyctl) that handles builds, deploys, secrets, and scaling. Fly.io supports any language or framework that runs in a container, with first-class support for Elixir, Rails, Node.js, Go, and Rust. Their managed services include Fly Postgres, LiteFS (distributed SQLite), Upstash Redis, and Tigris object storage. The free tier includes 3 shared-CPU VMs, 3 GB persistent storage, and 160 GB outbound bandwidth. Fly.io's unique Machines API allows programmatic control over VM lifecycle — start, stop, and scale individual instances in milliseconds. While more complex than traditional hosting, Fly.io offers performance characteristics impossible to achieve with single-region deployments.
Add a benchmark URL in admin and run the provider benchmark cron to display measured speed, security, and availability signals here.
Deploy to 30+ regions simultaneously — every user connects to the nearest instance for sub-50ms latency globally.
Same VM technology as AWS Lambda provides fast boot times and efficient resource usage.
3 shared VMs, 3 GB storage, and 160 GB bandwidth free — enough to run a small production application.
Programmatic control over VM lifecycle enables unique architectures like per-user VMs and on-demand scaling.
Any application that runs in Docker works on Fly.io — maximum flexibility in language and framework choice.
Requires familiarity with Docker, CLI tools, and distributed systems concepts — not beginner-friendly.
Usage-based pricing across compute, storage, bandwidth, and IPs can be hard to predict and budget for.
Fewer integrations, marketplace apps, and community resources compared to AWS, DigitalOcean, or Vercel.
Free tier support is community-only; paid support requires a launch plan or higher.