Does Neon Work With Fly.io?
Neon and Fly.io work excellently together—deploy your full-stack app on Fly.io and connect it to Neon's serverless PostgreSQL for a globally distributed, scalable architecture.
Quick Facts
How Neon Works With Fly.io
Neon and Fly.io complement each other perfectly in modern full-stack deployments. Fly.io runs your application servers in multiple regions worldwide, while Neon provides a serverless PostgreSQL database that scales automatically and supports branching for development workflows. You connect them by storing your Neon connection string as a Fly.io secret, then reference it in your app's environment variables. The beauty of this pairing is that Fly.io's edge compute brings your app logic close to users, while Neon handles database scaling transparently—no connection pooling headaches for most workloads, though you may want PgBouncer for very high connection counts. The free tiers are generous enough for hobby projects and MVPs: Neon gives you a shared compute instance with 3GB storage, and Fly.io offers 3 shared-cpu-1x VMs. Both platforms handle automatic scaling, so your infrastructure grows with your traffic without manual intervention.
Best Use Cases
Quick Setup: Node.js on Fly.io with Neon
npm install pg dotenvimport { Pool } from 'pg';
import dotenv from 'dotenv';
dotenv.config();
const pool = new Pool({
connectionString: process.env.DATABASE_URL,
max: 20,
idleTimeoutMillis: 30000,
connectionTimeoutMillis: 2000,
});
pool.query('SELECT NOW()', (err, res) => {
if (err) console.error('Connection failed:', err);
else console.log('Connected to Neon:', res.rows[0]);
pool.end();
});
// In fly.toml: env = { DATABASE_URL = "postgres://user:pass@ep-xxx.us-east-1.neon.tech/dbname" }
// Or use: fly secrets set DATABASE_URL="postgres://..."Known Issues & Gotchas
Connection pooling: Neon serverless connections can be slower on cold starts due to compute initialization
Fix: Use Neon's connection pooling feature (PgBouncer) for transaction or session-level pooling, or keep Fly.io app always-on with min_machines_running = 1
Cross-region latency: Neon has a single database location; queries from distant Fly.io regions experience higher latency
Fix: Choose your Neon region closest to your primary user base, or implement read replicas if Neon adds multi-region support
Free tier limits: Neon's compute hours reset monthly; heavy workloads can exceed free allocations quickly
Fix: Monitor compute usage in Neon console; upgrade to paid plan or optimize query performance and connection patterns
Network egress: Data transfer from Neon to Fly.io may incur charges on paid plans
Fix: Design efficient queries and use caching (Redis on Fly.io) to minimize database calls
Alternatives
- •Railway (database) + Fly.io (app)—Railway offers managed PostgreSQL with simpler pricing but less sophisticated branching
- •Vercel/Netlify (frontend) + Railway (full stack)—serverless functions instead of container-based compute, simpler but less flexible
- •Supabase (PostgreSQL + auth) + Fly.io—more features out-of-box but heavier and less minimal than Neon
Resources
Related Compatibility Guides
Explore more compatibility guides