# Limits

Cloudflare limits the number of distinct Dynamic Workers with in-flight requests. Multiple in-flight requests to the same Dynamic Worker count as one toward this limit.

| Context | Concurrent Dynamic Workers |
| --- | --- |
| Worker request | 4 |
| [Durable Object](/durable-objects/) | 10 (previously 4) |

In a Worker, each request has its own input/output (I/O) context. Each request can therefore have up to four distinct Dynamic Workers with in-flight requests.

A Durable Object shares one I/O context across all concurrent requests to the same object. Those requests can collectively have up to ten distinct Dynamic Workers with in-flight requests. To set lower CPU time or subrequest limits, refer to [Custom resource limits](/dynamic-workers/usage/limits/).