Railway: deployment failing silently [2026 fix]

Your build succeeds but service won't start—Railway cached old deps or missing PORT env var. Set PORT and force rebuild.

Railway: Deployment Failing Silently – Emergency Fix Guide

TL;DR

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Real Error Messages From Console Output

These are the exact patterns you'll see in Railway's deployment logs when this happens:

``` [1] ERROR: Service crashed immediately after startup [2] ERROR: Health check failed – service exited with code 1 [3] ERROR: No logs from service – process terminated [4] ERROR: Build succeeded but deployment marked as "Crashed" [5] ERROR: Listening on undefined – EADDRINUSE or port binding failed ```

Notice: No actual error message about *why* it crashed. That's the silent failure pattern.

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Broken vs. Fixed Code

Problem 1: Missing PORT Environment Variable

❌ BROKEN – Your Express/Node app: ```javascript const express = require('express'); const app = express();

app.get('/', (req, res) => { res.send('Hello'); });

// BROKEN: Assumes PORT from somewhere app.listen(process.env.PORT, () => { console.log(Server on port ${process.env.PORT}); }); ```

Railway can't infer PORT automatically like Heroku does. Result: process.env.PORT is undefined, app crashes.

✅ FIXED – Same app with fallback: ```javascript const express = require('express'); const app = express();

app.get('/', (req, res) => { res.send('Hello'); });

const PORT = process.env.PORT || 3000; app.listen(PORT, () => { console.log(Server on port ${PORT}); }); ```

AND in Railway dashboard → Variables → add PORT=3000.

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Problem 2: Stale Cached Dependencies

❌ BROKEN – Deployment config (railway.json or Procfile): ```json { "build": "npm ci", "start": "node index.js" } ```

If you updated a dependency locally but Railway's Docker layer cache picked up the old node_modules, your app loads outdated code and crashes silently.

✅ FIXED – Force fresh build: ```bash

Option 1: From CLI

Option 2: Dashboard → Deployments → [last deploy] → Redeploy → Force rebuild checkbox

Option 3: Add to railway.json to disable cache

Note on version specificity: This behavior is consistent in Railway as of 2026. Docker layer caching is a platform feature, not version-dependent. However, the exact UI location for "Force rebuild" may shift between dashboard redesigns—check [Railway docs](https://docs.railway.app/deployment/builds) for current UI.

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Problem 3: Wrong Node.js Version Specified

❌ BROKEN – package.json: ```json { "engines": { "node": "20.10.0" }, "dependencies": { "bcrypt": "^5.1.0" } } ```

Railway selects Node 16 by default. Native modules like bcrypt compiled for v16 won't load under v20. Silent crash.

✅ FIXED – Explicit Nixpack config:

Create nixpacks.toml: ```toml [build] only = ["npm"]

[phases.setup] rustVersion = "1.70"

[phases.build] cmds = [ "npm ci", "npm run build" ]

[[providers]] name = "node" version = "20.10.0" ```

Or set via dashboard: Settings → Environment → NODE_ENV=production + NODE_VERSION=20.10.0.

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Still Broken? Check These Too

1. Memory/CPU limits exceeded: Check Railway logs for OOMKilled or process timeout signals. Upgrade plan or optimize code. Logs are under Deployments → [Your Deployment] → Logs.

2. Database connection string missing: If your app needs Postgres/MySQL, Railway won't auto-inject credentials. Manually add DATABASE_URL to Variables, or add a database plugin to your Railway project.

3. Startup script mismatch: Your package.json has "start": "npm run build && node dist/index.js" but Railway executes plain node index.js. Set explicit Procfile or define start command in Railway dashboard.

Related troubleshooting: [Heroku to Railway migration guide](/?guide=heroku-to-railway) | [Environment variable not found errors](/?guide=railway-env-vars).

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Steps to Debug Now

1. Open Railway dashboard → Select project → Deployments tab 2. Click the failed deployment → "Logs" button 3. Search for Error, EADDRINUSE, undefined, or exited with code 4. If logs are empty/cut off: your process crashed before logging. Add console.log('Starting...') at the very top of your entry file 5. Verify PORT variable exists: Settings → Variables → confirm PORT=3000 6. Click "Redeploy" → check "Force rebuild" checkbox → Deploy 7. Wait 2-3 minutes and refresh logs

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Official Reference

📖 [Railway Deployments Guide](https://docs.railway.app/deployment/builds) 📖 [Railway Environment Variables](https://docs.railway.app/reference/environment-variables)

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Found a different variation? Drop it in the comments—Railway's behavior varies by language runtime (Python/Go silent fails differently) and we want your edge case logged here.