Railway: deployment failing silently [2026 fix]
Build succeeds but app won't start—missing Nixpacks config or PORT binding. Add railway.toml or set PORT env var.
Railway: Deployment Failing Silently [2026 Fix]
TL;DR
Cause: Your build completes but the app crashes on startup because Railway can't detect your runtime or PORT isn't bound. Fix: Addrailway.toml with explicit startCommand or set PORT environment variable in Railway dashboard.---
Real Console Error Messages
Error 1: Build succeeds, deployment immediately exits
``` [Railway] Build completed successfully [Railway] Container started [Railway] Application exited with code 1 [Railway] No logs available ```Error 2: Port binding failure (appears in logs if you dig deep)
``` Error: listen EADDRINUSE: address already in use :::3000 at Server.setupListenHandle [as _listen2] (net.js:1058:16) ```Error 3: Missing entrypoint detection
``` [Railway] Detecting runtime... [Railway] No start command found. Checking package.json... [Railway] ERROR: Could not determine how to start your application ```Error 4: Runtime incompatibility (Node version mismatch)
``` Command failed: npm start node: /lib64/libc.so.6: version `GLIBC_2.34' not found (required by node) ```Error 5: Environment variable not injected
``` listening on port undefined Error: Server must listen on a valid port number ```---
Broken Code → Fixed Code
Problem 1: No railway.toml, ambiguous start command
Broken (package.json only): ```json { "name": "my-app", "scripts": { "start": "node server.js", "dev": "nodemon server.js" }, "main": "server.js" } ```
Fixed (add railway.toml at project root): ```toml [build] builder = "nixpacks"
[start] command = "npm start"
[env] NODE_ENV = "production" PORT = "8080" ```
---
Problem 2: App doesn't listen on PORT environment variable
Broken (hardcoded port): ```javascript const express = require('express'); const app = express();
app.listen(3000, () => { console.log('Server running on port 3000'); }); ```
Fixed (use PORT env var): ```javascript const express = require('express'); const app = express(); const PORT = process.env.PORT || 3000;
app.listen(PORT, '0.0.0.0', () => {
console.log(Server running on port ${PORT});
});
```
---
Problem 3: Start script missing in package.json
Broken: ```json { "name": "api", "version": "1.0.0", "scripts": { "dev": "nodemon index.js" } } ```
Fixed: ```json { "name": "api", "version": "1.0.0", "scripts": { "start": "node index.js", "dev": "nodemon index.js" } } ```
---
Problem 4: Python app without Procfile equivalent
Broken (Django): ```python if __name__ == '__main__': app.run(debug=True, port=5000) ```
Fixed (railway.toml for Python): ```toml [build] builder = "nixpacks"
[start] command = "gunicorn config.wsgi:application --bind 0.0.0.0:$PORT"
[env] PORT = "8000" ```
---
Verification Steps
1. Check Railway build logs: Dashboard → Deployments → View Logs (expand all sections)
2. Verify PORT is set: Dashboard → Service → Variables → confirm PORT exists
3. Test locally: PORT=8080 npm start should work without errors
4. Check railway.toml syntax: Validate TOML format at [toml.io validator](https://www.toml-lint.com/)
---
Still Broken? Check These Too
1. Node version mismatch – Railway uses Nixpacks which auto-detects Node. If you need a specific version, add runtime.txt with node-20.10.0 (I'm uncertain if this syntax changed in 2026; verify against [Railway docs](https://docs.railway.app/guides/nixpacks))
2. Memory limits exceeded – Silent exits often mean OOM. Check Railway dashboard for memory spikes during startup. Increase plan or optimize bundle size.
3. Missing dependencies in production – Ensure all require()/import modules are in dependencies, not devDependencies. Run npm ls locally to verify.
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Related Guides
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Official References
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Found a different variation? Drop it in the comments—help us keep this guide current for 2026 deployments.