Cloudflare Workers is a serverless platform made by Cloudflare, Inc. Serverless means the developer uploads code and the provider runs it on demand, with no servers to rent or manage. Workers run in Cloudflare's data centers in more than 330 cities, close to users, and scale from zero to millions of requests.
Workers run inside V8 isolates (separate memory spaces inside one JavaScript engine process) instead of containers, which makes them lighter and avoids slow cold starts. Code is written in JavaScript, TypeScript, Python or Rust, and connects through bindings to Cloudflare databases, storage and AI models. The runtime, workerd, is open source, so code can be tested locally. Dynamic Workers start new Workers at runtime from code that is not known in advance, such as code written by an AI agent. They act as a lightweight sandbox for untrusted code: the host decides which bindings each one receives, can block or intercept its Internet access, and sets resource limits.
Workers is a hosted, pay-per-use service with a free plan. Dynamic Workers need the Workers Paid plan.