Edge Functions
Server code that runs in data centers closest to your user — making your app respond in milliseconds instead of seconds.
💡 In plain English: Instead of your app's brain being in one city, edge puts copies everywhere — so users in Tokyo get the same speed as users in New York.
Quick answer
Edge functions are server-side code that runs on a globally distributed network of servers, executing in the data center closest to each user. Unlike traditional servers in one location, edge functions run in 300+ locations worldwide with no cold starts.
What is Edge Functions?
Traditional servers run in one location — say, US East. A user in Tokyo waits 200ms just for the network round trip, before your code even runs. Edge functions solve this by running your code in 300+ data centers worldwide.
Edge functions use V8 isolates (the JavaScript engine from Chrome) instead of full virtual machines. They start in under 1ms with no cold starts, compared to 500ms-3s for traditional serverless functions.
Use edge for: auth middleware, redirects, A/B testing, API rate limiting. Don't use edge for: long-running tasks, heavy database queries, file processing.
In Vibe Coding
Cloudflare Workers is the most common edge runtime for vibe coders — gptsters.com runs on it. Vercel Edge Functions and Supabase Edge Functions are also popular. In Next.js, add 'export const runtime = "edge"' to any route to run it on the edge.
Example
For example: Your authentication middleware checks every request. Instead of running on one server in the US, it runs at the nearest edge location — so a user in London gets their request authenticated in 10ms instead of 200ms.
Why this matters
This matters because Edge Functions appears repeatedly when building, deploying, debugging, or connecting services in vibe coding workflows.
When you'll hit this in practice
You will usually run into Edge Functions when working on Pick Your Stack.
Simple edge function (Cloudflare Worker)
export default {
async fetch(request: Request): Promise<Response> {
const url = new URL(request.url)
if (url.pathname === '/api/hello') {
return Response.json({
message: 'Hello from the edge!',
location: request.cf?.country
})
}
return new Response('Not found', { status: 404 })
}
}Related Terms
Related Guides
Frequently Asked Questions
Edge runs in V8 isolates (fast, limited APIs). Serverless runs in full Node.js (slower startup, full features).
Yes — Cloudflare D1, Supabase, and PlanetScale all work from edge functions.