Last updated: January 12, 2026
Supabase is secure by design, but requires proper configuration. This guide covers the essential security steps for any Supabase-powered application.
Row Level Security is the foundation of Supabase security. Enable it on every table that contains data.
ALTER TABLE profiles ENABLE ROW LEVEL SECURITY;
ALTER TABLE posts ENABLE ROW LEVEL SECURITY;Use the (select auth.uid()) pattern for better performance. Test policies with different user contexts.
CREATE POLICY "Users read own profile" ON profiles
FOR SELECT TO authenticated
USING ((select auth.uid()) = id);The service_role key bypasses RLS. Never expose it in frontend code. Use it only in server-side functions.
Database functions should check authentication. Use SECURITY DEFINER carefully.
CREATE FUNCTION get_user_data()
RETURNS json AS $$
BEGIN
IF auth.uid() IS NULL THEN
RAISE EXCEPTION 'Not authenticated';
END IF;
-- function logic
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;Enable email confirmation, set password requirements, and configure rate limiting in the Supabase dashboard.
Query your database as an anonymous user to verify RLS is working. VAS does this automatically.
Avoid these common Supabase security pitfalls:
Use these tools to maintain security throughout development:
Security is an ongoing process, not a one-time checklist. After implementing these steps, use VAS to verify your Supabase app is secure before launch, and consider regular scans as you add new features.
Both return the current user's ID, but (select auth.uid()) is a subquery that evaluates once per query, while auth.uid() re-evaluates for every row. Use (select auth.uid()) in RLS policies for better performance, especially on large tables.
If you use service_role key (server-side), RLS is bypassed anyway. But if ANY part of your app uses the anon key or calls Supabase from the browser, you MUST have RLS. Best practice: always enable RLS even for server-only access, as defense in depth.
1) Check if RLS is actually enabled: SELECT relrowsecurity FROM pg_class WHERE relname = 'your_table'. 2) Check policies exist: SELECT * FROM pg_policies WHERE tablename = 'your_table'. 3) Test with SQL Editor using different roles (anon, authenticated).
Yes, RLS is perfect for multi-tenancy. Create a tenant_id column, then write policies like: USING ((select auth.jwt() ->> 'tenant_id') = tenant_id). This ensures users can only access data from their organization, enforced at the database level.