Replit Security Best Practices: Protect Your App
Replit makes coding accessible to everyone. But before you share your Repl with the world, you need to make sure it's secure. This guide covers the essentials.
What You'll Learn
- Replit's unique security considerations
- Managing secrets safely
- Database security
- Deployment security
- Common mistakes to avoid
Understanding Replit Security
Replit is a browser-based IDE that makes it easy to code, collaborate, and deploy. But its collaborative nature creates unique security challenges:
Replit-Specific Risks
- • Public Repls expose source code by default
- • Secrets may be visible in version history
- • Collaborators can see environment variables
- • Default configurations aren't always secure
Managing Secrets Safely
Replit provides a Secrets tool for storing sensitive values. Here's how to use it correctly:
Using Replit Secrets
- Click the "Secrets" tool in the left sidebar (lock icon)
- Add your API keys and passwords there, not in code
- Access them via environment variables in your code
# Python - accessing secrets
import os
api_key = os.environ.get('API_KEY')
// JavaScript - accessing secrets
const apiKey = process.env.API_KEY;
Never Do This
API_KEY = "sk-abc123..." # Hardcoded in code
If your Repl is public, anyone can see hardcoded secrets!
Database Security
If you're using Replit DB or an external database, protect your data:
Replit DB
- Replit DB is tied to your Repl—only your code can access it
- Don't store sensitive user data in Replit DB for production apps
External Databases
- Store connection strings in Secrets, never in code
- Use database-level security (RLS, roles, etc.)
- Enable SSL for database connections
Deployment Security
When deploying your Repl for production use:
- Make it private if it contains sensitive logic – Only make Repls public if you want to share the code
- Use Replit Deployments for production – More reliable than always-on Repls
- Set up a custom domain with HTTPS – Don't use the default .replit.dev for production
- Add security headers – Configure your web server to send proper security headers
Common Mistakes to Avoid
Committing Secrets to Git History
Even if you remove a secret from code, it may still be in your Repl's version history. Use Secrets from the start.
Public Repls with Sensitive Data
If your Repl is public, anyone can fork it and see your code. Make it private if it handles user data.
Trusting User Input
Always validate and sanitize user input. Never pass it directly to database queries or shell commands.
Replit Security Checklist
Scan Your Replit App
VAS automatically checks your deployed Repl for security vulnerabilities, exposed secrets, and missing protections.