Cloudflare Workers vs Fly.io: Edge Computing Tradeoffs
Cloudflare Workers runs at the edge in 300+ cities. Fly.io runs containers in ~30 regions. Compare performance, pricing, and DX.
Cloudflare Workers and Fly.io both run code close to users, but the execution models are very different. Understanding the difference is key to choosing the right platform.
Cloudflare Workers Model
Workers run in V8 isolates at Cloudflare's 300+ edge locations. Cold starts are ~5ms. Execution time is limited to 50ms CPU time (or 30s wall-clock with some products). You write JavaScript/TypeScript or WebAssembly.
Fly.io Model
Fly.io runs Firecracker microVMs in ~30 regions. Cold starts are faster than traditional containers (~100-500ms) but slower than Workers. No execution time limits. You run full Linux containers.
When Workers Win
- Pure edge logic (auth checks, A/B testing, geolocation routing)
- Ultra-low latency requirements in non-major regions
- JavaScript/TypeScript-first teams
- KV store, Durable Objects for state at the edge
When Fly.io Wins
- Full application runtimes (Node.js, Python, Go, etc.)
- Persistent connections (WebSockets, SSE, chatbots)
- Long-running processes
- State that doesn't fit the KV/DO model
- Full compatibility with any Linux binary
For OpenClaw AI Backends
Fly.io is the right choice. OpenClaw runs as a persistent process connecting to Telegram/Discord. Workers can't maintain persistent TCP connections. You need a real server, even if it's lightweight.
Complementary Use
Many teams use Workers for edge logic (routing, auth, rate limiting) and Fly.io for the application backend. This is a powerful combination — edge handles what it's best at, containers handle what they do best.