How it works
A Worker is a function that receives a web request and returns a response. Instead of containers, Workers run in V8 isolates, lightweight sandboxes inside one process, so they start in milliseconds and cost very little to keep ready. The same Worker can serve a site's static files for free, run an API, change pages on the way through, or run on a schedule with cron triggers.
Workers reach other Cloudflare services through bindings: KV and D1 for data, R2 for files, Durable Objects for per-room or per-user state (useful for chat and multiplayer), Queues, and Workers AI for models. The runtime speaks web standards (fetch, Request, Response) and supports many Node.js APIs through a compatibility flag, though not every npm package works. The runtime itself, workerd, is open source.
Cloudflare Workers pros and cons
Pros
- Near-instant starts and worldwide reach by default
- Low cost: 10 million requests a month are included in the $5 plan
- No bandwidth charges, and static asset requests are free
- Bindings to storage, queues and AI with no keys to manage
Cons
- Not full Node.js: some packages and native modules will not run
- CPU time limits per request, 10 ms on the free plan
- Code and data layout end up tied to Cloudflare's platform
When to use Cloudflare Workers
Pick it when
- APIs, webhooks and middleware that should answer quickly worldwide
- Full-stack sites that want static files and server code in one deploy
- Real-time features built on Durable Objects
Skip it when
- Heavy CPU work such as video encoding or long data jobs
- Code that depends on Node.js-only or native libraries
Cloudflare Workers pricing
Free tier
Free for 100,000 requests a day. The paid plan is $5 a month including 10 million requests and 30 million CPU milliseconds, then about $0.30 per extra million requests. No egress fees.
Cloudflare Workers pricing page (opens in a new tab)Approximate, checked September 2026.What the other tools cost
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