netlify-edge-functions

Run low-latency middleware at the edge by creating a TypeScript file under netlify/edge-functions/ that exports a default handler using the Context API. This executes geolocation-based routing close to users on the Deno runtime.

Choose edge functions over serverless when your application requires ultra-low latency, lightweight authentication checks, or A/B testing. Use serverless functions when you need heavier compute and memory constraints that exceed edge runtime limits.

Use the context.next() middleware pattern in Netlify edge functions to pass request handling down the chain, allowing you to manipulate requests and responses or apply logic like redirects before returning a final response.

Yes, Netlify edge runtime supports TypeScript and requires the Deno runtime to execute edge functions. You can write low-latency logic directly in TypeScript without additional build steps.

Edge functions are limited by compute and memory constraints, making them unsuitable for heavy processing. They are designed for lightweight, low-latency request handling such as middleware, personalization, and redirects.

Yes, you can run real-time A/B testing and personalization at the network edge. By executing logic close to globally distributed users, edge functions enable fast personalized responses without high latency.