Firebase vs Supabase Security
A comprehensive security comparison of the two most popular Backend-as-a-Service platforms. Understand the trade-offs and secure your apps correctly.
Quick Comparison
| Feature | Firebase | Supabase |
|---|---|---|
| Database Security | Security Rules (JSON) | Row Level Security (SQL) |
| Auth Providers | 20+ built-in | 10+ built-in |
| API Key Model | Public API key only | Anon + Service keys |
| Learning Curve | Rules syntax | SQL/Postgres |
| Common Mistake | Overly permissive rules | RLS disabled |
Database Security Comparison
Firebase Security Rules
Firebase uses a custom JSON-like rules language to define access control.
rules_version = '2';
service cloud.firestore {
match /databases/{db}/documents {
match /posts/{postId} {
allow read: if true;
allow write: if request.auth != null
&& request.auth.uid == resource.data.userId;
}
}
}Supabase Row Level Security
Supabase uses native PostgreSQL RLS policies written in SQL.
-- Enable RLS
ALTER TABLE posts ENABLE ROW LEVEL SECURITY;
-- Anyone can read
CREATE POLICY "Public read" ON posts
FOR SELECT USING (true);
-- Only owner can write
CREATE POLICY "Owner write" ON posts
FOR ALL TO authenticated
USING ((select auth.uid()) = user_id);Common Vulnerabilities by Platform
Firebase Common Mistakes
Using test rules in production
allow read, write: if true;Not validating data structure
allow write: if request.auth != null;Exposing admin collection
match /{document=**} { allow read; }Supabase Common Mistakes
Forgetting to enable RLS
CREATE TABLE users (...); -- No RLSUsing service_role in frontend
createClient(url, serviceRoleKey)SELECT policy without auth check
FOR SELECT USING (true)Authentication Comparison
| Feature | Firebase | Supabase |
|---|---|---|
| Email/Password | Yes | Yes |
| OAuth Providers | 20+ (Google, Apple, etc.) | 10+ (Google, GitHub, etc.) |
| Phone Auth | Yes (built-in) | Yes (via Twilio) |
| Magic Link | Custom implementation | Built-in |
| MFA | Yes | Yes |
| Custom Claims | Yes (server-side) | Yes (JWT metadata) |
| Anonymous Auth | Yes | Yes |
Which Should You Choose?
Choose Firebase If...
- You need real-time sync (Firestore excels here)
- You want tight Google Cloud integration
- You prefer NoSQL document structure
- You need Firebase ML or Analytics
Choose Supabase If...
- You prefer SQL and relational data
- You want PostgreSQL features (triggers, functions)
- You value open source and self-hosting options
- You need complex queries with JOINs
Security-wise, both can be equally secure when properly configured. The main difference is the mental model: Firebase rules are hierarchical and JSON-like, while Supabase uses familiar SQL. Choose based on your team's expertise and your app's data structure needs.
Frequently Asked Questions
Which is more secure, Firebase or Supabase?
Neither is inherently more secure. Security depends on correct configuration. Both have had apps compromised due to misconfigurations. The key is understanding your chosen platform's security model thoroughly.
Can I migrate security rules between platforms?
Not directly—they use different paradigms. Firebase rules are JSON-based with path matching; Supabase uses SQL policies. You'll need to rewrite rules, which is a good time to audit them.
Which has better security documentation?
Both have excellent documentation. Firebase has more examples due to its longer history. Supabase benefits from PostgreSQL's extensive RLS documentation.
Do I need to worry about API key exposure?
Firebase API keys and Supabase anon keys are both designed to be public. Security comes from your rules/policies, not from hiding these keys. Never expose Supabase's service_role key.
Verify Your BaaS Security
Whether you chose Firebase or Supabase, scan your app for misconfigurations and security issues.
Get Starter ScanLast updated: January 2025