Problem Statement
Compare API Routes in Pages Router with Route Handlers in App Router: what are the key differences?
Explanation
API Routes in Pages Router live in pages/api directory using a default export function receiving req and res Node.js-style objects where you manually set headers and status codes, while Route Handlers in App Router use route.js files with named HTTP method exports returning Web API Response objects following standard fetch patterns.
Route Handlers are more modern using Request and Response web standards, support streaming responses naturally, work with the Edge Runtime more easily, and integrate better with Server Components and Server Actions.
API Routes are simpler for developers familiar with Express.js patterns and work well for traditional REST APIs, but Route Handlers provide better TypeScript support, cleaner syntax for modern APIs, and better alignment with web standards.
Both can coexist in the same project during migration, and you can choose based on whether you're using Pages or App Router.
