Edge Computing for Developers: Cloudflare Workers vs Deno Deploy vs Fastly Compute

Edge computing promises the holy grail: your code runs physically close to your users, cutting latency from hundreds of milliseconds to single digits. In 2026, three platforms dominate the developer edge computing space — Cloudflare Workers, Deno Deploy, and Fastly Compute. Each makes different tradeoffs.

This is the comparison you’d write after actually building on all three.

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The Edge Computing Mental Model

Traditional serverless (Lambda, Cloud Functions) runs in one or a few regions. You choose us-east-1, your users in Tokyo hit your function from 150ms away. Edge computing distributes your code across a global network of Points of Presence (PoPs) — 200+ for the major platforms — so Tokyo users hit a Tokyo node at ~5ms.

The catch: you’re trading flexibility for speed. Edge runtimes aren’t Node.js. They don’t have fs, full net, or arbitrary npm packages. They run in constrained environments optimized for fast startup and low memory.

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Platform Overview

Cloudflare Workers

Architecture: V8 Isolates + optional Wasm PoPs: 330+ Runtime: WinterCG-compatible JavaScript/TypeScript (subset of Web APIs) Cold starts: ~0ms (isolates, not processes) Free tier: 100,000 req/day, 10ms CPU per request

Cloudflare Workers is the largest edge platform by PoP count and the most mature developer ecosystem. Workers runs in V8 isolates — the same engine as Chrome — which means near-zero cold starts and ~128MB memory per isolate.

The ecosystem is substantial: Workers KV (global key-value), Durable Objects (stateful coordination), R2 (S3-compatible storage), D1 (SQLite at the edge), Queues, Hyperdrive (database connection pooling). If you need a full backend at the edge, Workers has more primitives than any competitor.

// Cloudflare Worker — TypeScript
export default {
  async fetch(request: Request, env: Env): Promise<Response> {
    const url = new URL(request.url);

    // Read from KV
    const cached = await env.CACHE.get(url.pathname);
    if (cached) {
      return new Response(cached, {
        headers: { "X-Cache": "HIT", "Content-Type": "application/json" },
      });
    }

    // Fetch from origin
    const data = await fetch(`https://api.example.com${url.pathname}`);
    const json = await data.text();

    // Write to KV with TTL
    await env.CACHE.put(url.pathname, json, { expirationTtl: 300 });

    return new Response(json, {
      headers: { "X-Cache": "MISS", "Content-Type": "application/json" },
    });
  },
};

# wrangler.toml
name = "my-worker"
main = "src/index.ts"
compatibility_date = "2026-01-01"

[[kv_namespaces]]
binding = "CACHE"
id = "your-kv-namespace-id"

Deploy with wrangler deploy. Workers routes requests globally in milliseconds.

Deno Deploy

Architecture: V8 Isolates PoPs: 35 Runtime: Deno (Web APIs + Deno-specific APIs, no npm by default — use npm: specifiers) Cold starts: ~1ms Free tier: 1M requests/month, 10ms CPU per request

Deno Deploy is the hosted version of the Deno runtime. If you’re already writing Deno applications, it’s the zero-friction deployment target. The DX is exceptional: push to GitHub, auto-deploy, instant preview URLs per branch.

The runtime has better Node.js compatibility than it did in 2022 — npm: specifiers let you use most npm packages directly:

// Deno Deploy — TypeScript
import { serve } from "https://deno.land/[email protected]/http/server.ts";
import { createClient } from "npm:@supabase/supabase-js@2";

const supabase = createClient(
  Deno.env.get("SUPABASE_URL")!,
  Deno.env.get("SUPABASE_ANON_KEY")!
);

serve(async (req: Request) => {
  const url = new URL(req.url);

  if (url.pathname === "/api/posts") {
    const { data, error } = await supabase
      .from("posts")
      .select("*")
      .order("created_at", { ascending: false })
      .limit(10);

    if (error) return new Response(error.message, { status: 500 });
    return Response.json(data);
  }

  return new Response("Not found", { status: 404 });
});

Deploy: deployctl deploy --project=my-project main.ts. That’s it. No config files, no build step.

Deno Deploy’s weakness is PoP count — 35 vs Cloudflare’s 330. For most applications this is fine (35 PoPs still covers major population centers), but if you’re optimizing for last-mile latency globally, Cloudflare wins.

Fastly Compute

Architecture: WebAssembly (wasmtime) PoPs: 80+ Runtime: Wasm (Rust, JavaScript via StarlingMonkey, Go, C/C++) Cold starts: ~0ms (Wasm, no process initialization) Free tier: 50,000 req/month, 50ms compute per request

Fastly Compute is the only major edge platform that runs Wasm natively as its primary model (not a secondary option). This means:

• True language flexibility: write in Rust, Go, TypeScript, or anything that compiles to Wasm
• Deterministic execution: Wasm’s sandbox guarantees consistent behavior
• No cold starts: Wasm modules initialize faster than V8 isolates

The tradeoff: Fastly’s ecosystem is smaller. No native KV store comparable to Workers KV. Fewer integrations. The Rust SDK is excellent; the JavaScript (Starling Monkey) SDK is newer.

// Fastly Compute — Rust
use fastly::http::{header, Method, StatusCode};
use fastly::{Error, Request, Response};

#[fastly::main]
fn main(req: Request) -> Result<Response, Error> {
    // Only handle GET requests
    if req.get_method() != Method::GET {
        return Ok(Response::from_status(StatusCode::METHOD_NOT_ALLOWED));
    }

    // Send request to origin backend
    let backend_resp = req
        .clone_without_body()
        .send("origin_backend")?;

    // Add CORS headers
    let mut resp = backend_resp;
    resp.set_header(header::ACCESS_CONTROL_ALLOW_ORIGIN, "*");

    Ok(resp)
}

# fastly.toml
manifest_version = 3
name = "my-compute-app"
language = "rust"

[setup.backends.origin_backend]
address = "api.example.com"
port = 443

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Cold Start Benchmarks

Cold starts are where edge platforms differentiate from regional serverless:

Platform	Cold Start (p50)	Cold Start (p99)
Cloudflare Workers	~0ms	~5ms
Deno Deploy	~1ms	~15ms
Fastly Compute (Wasm)	~0ms	~1ms
AWS Lambda (Node.js)	~100ms	~800ms
Google Cloud Functions	~150ms	~1200ms

Both V8-isolate platforms (Workers, Deno Deploy) and Wasm (Fastly) achieve effectively zero cold starts because they don’t spin up OS processes — they instantiate a new isolate or module instance in an already-running process.

This is the fundamental advantage over regional serverless: every request to your edge function arrives at an already-warm runtime.

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Latency by Region

For a simple API endpoint (no database, pure compute):

User Location	Cloudflare Workers	Deno Deploy	Fastly Compute	AWS Lambda us-east-1
New York	5ms	8ms	12ms	25ms
London	4ms	6ms	9ms	110ms
Tokyo	3ms	18ms	22ms	165ms
Sydney	4ms	25ms	35ms	220ms
São Paulo	5ms	20ms	28ms	180ms

These are representative figures; actual numbers vary with network conditions.

Cloudflare’s 330+ PoP lead shows in Asia-Pacific and South America, where Deno Deploy’s 35 PoPs create longer hops.

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When to Choose Each Platform

Choose Cloudflare Workers when:

• You need maximum PoP coverage (330+)
• You want edge-native storage (KV, Durable Objects, R2, D1)
• You’re building a full backend at the edge (not just middleware)
• You need Cloudflare’s DDoS protection, bot management, or CDN bundled with compute
• Your team knows JavaScript/TypeScript

Choose Deno Deploy when:

• You’re already using Deno for development
• You want the best developer experience and fastest iteration cycle
• You’re building API routes or SSR for a Deno/Fresh application
• You need good npm ecosystem compatibility
• Latency in APAC/LatAm is not your top concern

Choose Fastly Compute when:

• You want to write edge logic in Rust or Go (not just JavaScript)
• You need deterministic, auditable execution (Wasm’s sandbox provides this)
• You’re building request/response manipulation at CDN level
• Security and isolation are critical requirements

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Limitations to Know Before You Commit

All edge platforms share common constraints:

No long-running processes. CPU time limits range from 10ms (Workers free tier) to 50ms (Fastly free tier) to 30s (Workers paid). Background tasks and long polling don’t work.

No arbitrary TCP/UDP. You can’t open raw sockets. HTTP requests to external services work; raw database connections (PostgreSQL, MySQL) typically require an HTTP proxy layer (Hyperdrive for Workers, Supabase for Deno Deploy).

Limited file system. Wasm components can have controlled fs access via WASI, but V8 isolate platforms have no fs at all. Bundle your assets into the deployment artifact.

Package compatibility. Many npm packages assume Node.js APIs (fs, net, crypto) that don’t exist in edge runtimes. Check edge-runtime.dev compatibility tables before committing.

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Pricing Comparison (2026)

Platform	Free Tier	Paid Base	Additional Requests
Cloudflare Workers	100K req/day	$5/month (10M req)	$0.50/million
Deno Deploy	1M req/month	$20/month (5M req)	$2/million
Fastly Compute	50K req/month	Pay-as-you-go	$0.095/M req + $0.005/M req-seconds

For low-traffic projects, Cloudflare’s free tier is the most generous. For high-volume API traffic, Fastly’s per-request pricing can be competitive. Deno Deploy’s pricing is more expensive per-request but includes features like GitHub integration and preview environments.

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Code Example: A/B Testing at the Edge

This pattern shows where edge computing genuinely shines — request-level logic that runs before your origin, with zero added latency:

// Cloudflare Worker — A/B testing
export default {
  async fetch(request: Request, env: Env): Promise<Response> {
    const url = new URL(request.url);

    // Only A/B test the homepage
    if (url.pathname !== "/") {
      return fetch(request);
    }

    // Stable bucket assignment using cookie
    let bucket = request.headers.get("Cookie")?.match(/ab_bucket=([ab])/)?.[1];

    if (!bucket) {
      bucket = Math.random() < 0.5 ? "a" : "b";
    }

    // Route to variant
    const variantUrl = bucket === "b"
      ? new URL("/v2/", url.origin)
      : url;

    const response = await fetch(new Request(variantUrl, request));

    // Persist bucket assignment
    const newResponse = new Response(response.body, response);
    newResponse.headers.append(
      "Set-Cookie",
      `ab_bucket=${bucket}; Path=/; Max-Age=86400`
    );
    newResponse.headers.set("X-AB-Bucket", bucket);

    return newResponse;
  },
};

This runs at 330+ edge nodes with zero cold starts. The equivalent Lambda function would add 100-200ms to every uncached request.

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The Verdict

Cloudflare Workers is the default choice for most teams. The ecosystem depth, PoP coverage, and generous free tier make it hard to beat. If you’re starting fresh and don’t have strong language preferences, Workers is the safe pick.

Deno Deploy is the best developer experience if you’re in the Deno ecosystem. The instant preview deployments and tight GitHub integration make iteration fast. The 35-PoP limitation matters for global applications but not for most use cases.

Fastly Compute is the right choice when you need Wasm — for Rust/Go logic, for security-critical sandboxing, or for deterministic execution guarantees. It’s also the best platform for CDN-level request manipulation where you need Fastly’s VCL-like control with modern developer tooling.

None of these platforms will replace your database or long-running services. But for latency-sensitive API logic, auth checks, personalization, and request routing, edge computing in 2026 is production-ready and worth the migration cost.