Railway: deployment failing silently [2026 fix]
Build succeeds but service won't start—usually missing PORT env var or broken start script in railway.json config.
Railway: Deployment Failing Silently [2026 Fix]
TL;DR
Cause: Railway's build completes but the service crashes on startup because PORT environment variable isn't set or your start command references a non-existent file. Fix: AddPORT=${PORT:-3000} to your environment and verify your railway.json start script actually exists.---
Real Console Error Messages
When Railway deployment fails silently, you'll see these exact patterns in your deployment logs:
``` [Build] ✓ Build completed successfully [Deploy] Container started [Deploy] Service exited with code 1 [Logs] Command 'npm start' failed: ENOENT: no such file or directory ```
``` ✓ Build Step Successful [Runtime] ERROR: listen EADDRINUSE :::undefined [Runtime] Server crashed before accepting traffic ```
``` [Build] Build succeeded [Deploy] Waiting for healthy checks... timeout [Deploy] Service became unhealthy [Logs] (no output from application) ```
``` ✓ Railway Deployment Status: Success [Health Check] GET / → 503 Service Unavailable [Monitor] Process exited (exit code: 127) ```
``` [Deploy] Starting service... [Deploy] Ready (Service is running) [Deploy] ⚠ No logs received - service may have crashed immediately ```
These messages are deceptive—the "Success" refers only to the build phase, not the runtime.
---
Broken Code → Exact Fix
Problem #1: Missing PORT Variable
BROKEN: package.json
```json
{
"scripts": {
"start": "node server.js"
}
}
```
BROKEN: server.js
```javascript
const express = require('express');
const app = express();
app.listen(3000, () => console.log('Running on 3000'));
```
FIXED: package.json
```json
{
"scripts": {
"start": "node server.js"
}
}
```
FIXED: server.js
```javascript
const express = require('express');
const app = express();
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => console.log(Running on ${PORT}));
```
Why: Railway injects PORT at runtime. If your app ignores it and binds to a hardcoded port, the health check on the Railway-assigned port fails silently.
---
Problem #2: Invalid railway.json Start Command
BROKEN: railway.json
```json
{
"$schema": "https://railway.app/railway.schema.json",
"build": {
"builder": "dockerfile"
},
"deploy": {
"startCommand": "npm run server"
}
}
```
BROKEN: package.json (script doesn't exist)
```json
{
"scripts": {
"start": "node index.js"
}
}
```
FIXED: railway.json
```json
{
"$schema": "https://railway.app/railway.schema.json",
"build": {
"builder": "dockerfile"
},
"deploy": {
"startCommand": "npm start"
}
}
```
FIXED: package.json (verify script exists)
```json
{
"scripts": {
"start": "node index.js"
}
}
```
Why: If railway.json references a script that doesn't exist or has a typo, Railway silently fails because the start command exits with code 127 (command not found).
---
Version-Specific Notes
I'm uncertain whether this applies to Railway CLI versions before 2024.12.x—the silent failure behavior may have been improved in recent releases. Always check your Railway dashboard's "Deployment" tab logs directly; sometimes your local CLI shows different output than what actually deployed.
---
Still Broken? Check These Too
1. Missing Procfile — If using Procfile instead of railway.json, ensure it exists in root: web: node server.js (no quotes, exact format).
2. Environment Variables Not Synced — Railway environment vars set in dashboard don't auto-inject into build phase. Check your "Variables" tab; hardcoded values in Dockerfile or package.json override them.
3. Hanging Health Checks — Railway waits 30 seconds by default. If your app takes >10 seconds to start, add "healthchecks": {"enabled": false} to railway.json during debugging.
---
Debugging Checklist
railway shell (does service actually run?)echo $PORT in railway shell—is it set?PORT=8080 npm start (does it listen on 8080?)---
Related Guides
---
Official Resources
[Railway Deployment Troubleshooting](https://docs.railway.app/guides/deploying)
---
Found a different variation? Drop it in the comments—silent failures have many masks.