Edge functions run your server-side code at CDN points of presence around the world, close to your users. Instead of a request traveling from Tokyo to a server in Virginia, the code runs at an edge node in Tokyo. The result is lower latency for dynamic content — personalization, A/B testing, authentication, and API responses that feel instant.
I deployed the same application across Vercel Edge Functions, Cloudflare Workers, and Deno Deploy to compare the developer experience, performance, and limitations.
When Edge Functions Make Sense
Edge functions are ideal for lightweight compute that benefits from proximity to users: authentication checks, redirects, header manipulation, personalization, geolocation-based content, and API endpoints that do not need a database round-trip.
They are not ideal for database-heavy operations (your database is probably in one region, not globally distributed), long-running computations, or applications that depend on Node.js APIs not available in the edge runtime.
Vercel Edge Functions
Vercel Edge Functions integrate tightly with Next.js. Any Next.js route handler or middleware can run at the edge by adding export const runtime = 'edge'. The deployment experience is seamless — push to git, Vercel builds and deploys to its global edge network automatically.
The middleware use case is Vercel’s strongest. Authentication, internationalization, feature flags, and request rewriting all happen at the edge before the page renders. For Next.js applications, this means personalized pages with no cold start penalty for the user.
Edge Functions use the Web API standard (fetch, Request, Response, Headers) rather than Node.js APIs. This limits which npm packages work — anything that depends on Node.js-specific APIs (fs, net, crypto in some forms) will not run. The Vercel Edge Runtime documentation lists supported APIs.
Performance is competitive. Cold starts are under 10ms, and execution times are fast for compute-light tasks. The global distribution covers major population centers, though the number of edge locations is smaller than Cloudflare’s network.
Best for
Next.js applications that need edge middleware for authentication, personalization, and A/B testing. Teams already deploying on Vercel who want to add edge compute incrementally.
Cloudflare Workers
Cloudflare Workers run on the largest edge network — over 300 locations worldwide. The V8 isolate model (same as Chrome) means near-zero cold starts (under 5ms) and fast execution. Workers are not containers; they are lightweight isolates that start almost instantly.
The platform is the most complete. Workers KV provides globally distributed key-value storage. Durable Objects offer strongly consistent, stateful compute at the edge. R2 provides S3-compatible object storage. D1 is an edge-distributed SQLite database. Queues handle asynchronous message processing. Together, these primitives let you build complete applications at the edge.
Wrangler (the CLI) provides local development with Miniflare, which simulates the Workers runtime locally. The development experience is fast — edit, test locally, deploy in seconds. The integration with git-based CI/CD works smoothly alongside your existing deployment pipelines.
The pricing model is generous for small projects. The free tier includes 100,000 requests per day. Paid plans start at $5/month for 10 million requests, which covers most applications.
The limitation is the runtime environment. Workers use the Web API standard, not Node.js. The compatibility layer has improved significantly (node:crypto, node:buffer are supported), but complex Node.js applications may need adaptation. The 128MB memory limit and 30-second CPU time limit constrain what you can do per request.
Best for
Applications that need the widest global distribution and lowest latency. Projects that can use Cloudflare’s storage primitives (KV, D1, R2) to keep data close to the edge. API backends, authentication services, and content transformation pipelines. Security-sensitive applications benefiting from Cloudflare’s WAF and DDoS protection.
Deno Deploy
Deno Deploy runs Deno (the TypeScript-first JavaScript runtime) at the edge. If you write TypeScript, the developer experience is the cleanest of the three — no build step, no bundler configuration, native TypeScript support. Import modules by URL, deploy, and it runs.
The Fresh framework (Deno’s web framework) is designed for Deno Deploy. It provides island-based architecture similar to Astro, with server-rendered pages and selective client hydration. The result is fast pages with minimal JavaScript.
Deno KV provides a globally distributed key-value store with strong consistency, similar to Cloudflare’s Durable Objects but with a simpler API. For applications that need shared state at the edge (session storage, feature flags, rate limiting), Deno KV is practical and well-integrated.
The npm compatibility has improved significantly. Most npm packages work through the npm: specifier, and the compatibility gap that limited Deno’s adoption in earlier years has largely closed.
The edge network is smaller than Cloudflare’s (35+ regions vs 300+), so latency in less-served regions may be higher. For applications with primarily US, European, and Asian traffic, coverage is sufficient.
Best for
TypeScript-first teams that want the cleanest developer experience. Projects using the Fresh framework. Applications that benefit from Deno KV for edge-distributed state.
Verdict
Cloudflare Workers is the most capable edge platform. The network size, storage primitives, and near-zero cold starts make it the strongest option for building complete edge applications.
Vercel Edge Functions is the best for Next.js applications. The integration is seamless, and the middleware pattern covers the most common edge use cases without architectural changes.
Deno Deploy is the best for TypeScript-first development. The developer experience is the cleanest, and Deno KV provides practical edge state management.
For most teams, the choice follows the framework: Next.js teams use Vercel, everyone else evaluates Cloudflare Workers first. The edge is not a requirement for every application, but for latency-sensitive user-facing features, it is a meaningful improvement.
About Brian Detering
Brian Detering is a software engineer, educator, and tech writer based in Los Angeles. He teaches programming and software engineering at the University of Southern California, where his work spans programming languages, systems architecture, and applied AI. With over a decade of hands-on experience building production systems, Brian writes about the tools and workflows that actually make developers more productive — from CI/CD pipelines and containerization to API testing and security best practices. When he's not teaching or writing code, he's usually benchmarking the latest dev tools or tinkering with homelab infrastructure.
