Vercel Edge Functions
Edge & ServerlessServerless functions running at the edge on Vercel's network
Features
- V8 isolate runtime with zero cold starts
- Global edge deployment across Vercel's network
- Web-standard APIs (Request, Response, fetch)
- Streaming responses for real-time output
Pros
- Zero cold starts unlike traditional serverless
- Seamless Next.js middleware and API route integration
- Simple deployment through Vercel platform
Cons
- Limited Node.js API compatibility
- CPU and memory limits stricter than serverless functions
- Tied to Vercel platform
Overview
Vercel Edge Functions run serverless code at the edge of Vercelās global network, providing low-latency responses to users worldwide. Built on V8 isolates (similar to Cloudflare Workers), they offer zero cold starts and web-standard APIs.
Edge Functions are particularly powerful when used with Next.js. They power Next.js middleware for request-time logic like authentication, redirects, A/B testing, and internationalization. They can also be used as API routes when latency is more important than full Node.js API compatibility.
Edge Functions use web-standard APIs (Request, Response, fetch, crypto) rather than Node.js APIs, which makes them fast but limits compatibility with Node.js-specific packages.
When to Use
Choose Vercel Edge Functions for latency-sensitive logic in Next.js applications: middleware, authentication checks, A/B testing, and lightweight API endpoints. For compute-heavy or Node.js-dependent workloads, use Vercelās standard serverless functions instead.
Getting Started
// app/api/hello/route.ts
export const runtime = 'edge'
export function GET(request: Request) {
return new Response(JSON.stringify({ hello: 'world' }), {
headers: { 'content-type': 'application/json' }
})
}