Limits and Instance Types

The memory, vCPU, and disk space for Containers are set through instance types. You can use one of six predefined instance types or configure a custom instance type.

For an application that uses the default scheduling policy, specify the size with the instance_type property in your Worker's Wrangler configuration file. For the durable_object policy, pass the named size to ctx.container.start() with the runtime instance property.

In addition to the predefined instance types, you can configure custom instance types. Field names depend on where you configure the size. Wrangler configuration for the default policy uses vcpu, memory_mib, and disk_mb. A ctx.container.start() call for the durable_object policy uses vcpu, memoryMib, and diskMb.

Refer to the Wrangler configuration documentation or scheduling policy documentation for examples.

Custom instance types have the following constraints:

For workloads requiring less than 1 vCPU, use the predefined instance types such as lite or basic.

The following limits apply per account:

Cloudflare limits each HTTP request body forwarded from a Container to an external service through an outbound handler to 100 MiB by default.

This limit applies to each request body, including encoding and multipart form fields. It does not limit the total size of a file uploaded through separate requests. The destination service can impose additional limits.

The Maximum Upload Size setting for your application's custom domain does not control this limit. A larger upload accepted by your domain can still be rejected when your Container or Durable Object sends it to another service.

For larger uploads, use the destination's multipart or resumable upload API. Keep each request body below the limit. If you already use multipart uploads, reduce the part size. Streaming, HTTP chunked transfer encoding, and multipart/form-data do not bypass the limit on a single request body.

To request a higher outbound limit, contact your account team or Cloudflare Support. Specify that the request concerns outbound HTTP uploads from Containers or Durable Objects. Increases are subject to review.

Include the following information:

• The account ID and Worker name for the affected workload.
• The Container instance ID or Durable Object namespace and ID.
• The destination hostname.
• The failing request body size in bytes and the requested limit.
• The failure timestamp, relevant error logs, and a minimal reproduction.

For upload failures, refer to Troubleshoot outbound uploads.

The following limits apply to Container snapshots:

Restoring a snapshot refreshes its 30-day time-to-live.