Route Handler vs Direct Data Access From a Server Component

Calling the route handler is always faster because Next.js caches internal HTTP requests more aggressively than direct function calls.

Direct database calls are disallowed inside Server Components; all data access must go through a route handler regardless of origin.

Since Server Components execute on the server, there is no cross-origin restriction requiring a route handler as an intermediary — calling the app's own route handler via fetch adds an unnecessary internal HTTP round-trip compared to invoking the database client directly, which is why the framework's own guidance favors direct access for data a Server Component can reach itself.

Route handlers execute in a separate runtime that has access to environment variables unavailable to Server Components, making them mandatory for database access.