Replit Security Checklist
Last updated: January 12, 2026
Use this checklist to ensure your Replit application is secure before launch. 7 critical items require immediate attention.
Why This Security Checklist Matters
Security checklists serve as systematic guides for identifying vulnerabilities that might otherwise be overlooked during rapid development cycles. For Replit applications specifically, this checklist addresses the most common security gaps that emerge when using AI-assisted development workflows.
Research from multiple security organizations indicates that approximately 80% of AI-built applications contain at least one exploitable vulnerability at launch. The vulnerabilities are often predictable—they follow patterns that this checklist is designed to catch. By systematically reviewing each item, you significantly reduce the risk of launching an insecure application.
Unlike generic security checklists, this guide focuses specifically on vulnerabilities prevalent in Replit applications. Each item has been prioritized based on real-world attack patterns and the potential impact of exploitation. Critical items should be addressed before any production deployment.
Critical Priority
Critical items can lead to complete application compromise, data breaches, or unauthorized access to all user accounts. These must be addressed before deploying to production. Attackers actively scan for these vulnerabilities.
High Priority
High priority items represent significant security risks that could allow unauthorized access to sensitive data or functionality. While not immediately catastrophic, these vulnerabilities should be fixed as soon as possible.
Medium/Low Priority
Medium and low priority items strengthen your overall security posture. While they may not be immediately exploitable, addressing them prevents attack chains and defense-in-depth gaps.
Manual vs Automated Security Checking
While manual security reviews are thorough, they're time-consuming and prone to human error. Automated scanning catches common vulnerabilities instantly, freeing you to focus on business logic and complex security decisions.
Items VAS Automates
- Exposed API keys and secrets in JavaScript bundles
- HTTP security header configuration
- Supabase RLS policy testing
- Firebase Security Rules validation
- Cookie security attributes
Manual Review Still Required
- Business logic vulnerabilities
- Custom authentication implementations
- Access control logic in API routes
- Data validation requirements
- Third-party integration security
Code Visibility
Use paid tier for private Repls
Free Repls are public by default - anyone can see your source code
Never work on sensitive projects on free tier
Public visibility means your code, logic, and potential secrets are exposed
Check Repl visibility settings
Verify each Repl's visibility setting before adding sensitive code
Review forked Repls
Forks may expose your code if visibility settings differ
Secret Management
Use Replit Secrets for all credentials
AutoStore API keys, database URLs, and passwords in Secrets, not in code
Never hardcode secrets in source files
AutoEven in private Repls, hardcoded secrets can be accidentally exposed
Access secrets via environment variables
Use process.env or os.environ to access secrets in your code
Rotate secrets if potentially exposed
If you ever had a secret in public code, rotate it immediately
Database Security
Use secure database connections
Always use SSL/TLS for database connections from Replit
Store connection strings in Secrets
AutoDatabase URLs contain credentials - never hardcode them
Configure database access controls
Set up proper authentication and authorization on your database
Use IP allowlisting if available
Some databases allow restricting access to specific IPs
Deployment Security
Review Replit deployments settings
Understand what's exposed when you deploy a Repl
Configure custom domain with HTTPS
AutoUse HTTPS for all production deployments
Set up proper authentication for web apps
Don't rely on obscurity - implement real authentication
Monitor deployed Repls for issues
Regularly check logs and usage for your deployed applications
Don't Check Manually
VAS automatically checks 4 of these 16 items. Get instant results with detailed remediation guidance.
Run Automated Security ScanFrequently Asked Questions
Why is the free tier a security concern?
Free Repls are public by default - anyone can view your source code. Even with Replit Secrets, your code logic, database schemas, and potential vulnerabilities are visible. Always use paid tiers for production or sensitive development.
How do I use Replit Secrets correctly?
Add secrets in the Secrets tab, not in your code. Access them via process.env (Node.js) or os.environ (Python). Never print secrets to console or include them in error messages. Remember that on free tier, surrounding code is still public.