Server Actions vs API Routes in Next.js 14: When to Use What?

Next.js 14 introduced Server Actions as a powerful alternative to traditional API Routes. While both can be used to handle server-side logic, they are designed for different use cases. In this article, we’ll explore the key differences between Server Actions and API Routes — and when you should use one over the other.

What Are API Routes?

API Routes in Next.js allow you to create RESTful endpoints inside the pages/api or app/api directory. They run exclusively on the server and are typically used to handle requests from the client or external services.

// app/api/hello/route.ts
export async function GET() {
  return Response.json({ message: 'Hello from API route' });
}

Use Cases for API Routes

• Handling HTTP requests (GET, POST, PUT, DELETE)
• Building REST APIs
• Accepting webhooks
• Handling form submissions via fetch

What Are Server Actions?

Server Actions are a new experimental feature introduced in Next.js 13 and improved in v14. They allow you to define server-side logic directly within your components or actions files, and invoke them without setting up a separate API route.

'use server';

export async function saveForm(data: FormData) {
  const name = data.get('name');
  // Do something with name
}

You can then use it in a form:

<form action={saveForm}>
  <input name="name" />
  <button type="submit">Submit</button>
</form>

Use Cases for Server Actions

• Server-side form handling
• Calling database logic from the UI
• Keeping logic close to the component
• Simplifying full-stack code in small projects

Key Differences

Feature	API Routes	Server Actions
Location	app/api or pages/api	Inline in client/server components
Triggered by	HTTP requests (fetch, axios)	Form submissions or programmatically
Data format	JSON (usually)	FormData
Best for	REST APIs, integrations	Simple actions, internal logic
Requires endpoint?	Yes	No
Streaming support	Not built-in	Native with Server Components

When Should You Use Each?

Use Server Actions if:

• You're working with forms and want a simple, end-to-end solution.
• You need tight integration between UI and server logic.
• Your action doesn't require a public API endpoint.
• You want to avoid unnecessary client-side JS for form handling.

Use API Routes if:

• You need to expose a public API.
• You're integrating with third-party services (e.g. Stripe webhooks).
• You're building a REST or GraphQL backend.
• You want to decouple frontend from backend logic.

Can They Work Together?

Absolutely! You can mix both approaches in the same project.

For example:

• Use Server Actions for internal form handling and saving data to your DB.
• Use API Routes for exposing endpoints to mobile apps, external tools, or handling payments.

Final Thoughts

Server Actions are a great step forward in simplifying full-stack development with Next.js. However, API Routes are still very much relevant — especially for more traditional use cases involving external clients and structured APIs.

👉 Choose the tool that best fits the use case — and don’t be afraid to mix them.