Next.js Server Actions vs API Routes: Architecture, Performance, and Use Cases

With the introduction of the App Router, Next.js added two powerful server-side primitives: Server Actions Route Handlers At first glance, they might seem interchangeable—both run on the server. But they're designed for different responsibilities , follow different execution models , and come with different constraints . Understanding these differences is essential to avoid architectural pitfalls and performance issues. What Are Server Actions? According to the official documentation, Server Act