---
title: Bandwidth Limit
description: >-
  Paces the responses sent to each client (by IP address) to a number of bytes
  per second.
---
> ## Documentation Index
> Fetch the complete documentation index at: https://docs.page/luizfonseca/super/llms.txt
> Use this file to discover all available pages before exploring further.

Paces the responses of a location to each client (by IP address): the first `burst` bytes go at full speed, then `rate` bytes per second. A client's responses share its limit, so ten downloads at once share `rate` rather than getting ten times it.

Responses aren't refused or cut: they're sent more slowly. It applies to responses from upstreams, from the [cache](/use-cases/cache) and from [`static_files`](/plugins/static-files).

## Options

| Name | Description |
| --- | --- |
| `rate` | Bytes per second for each client, such as `"512KiB"` or `"1MiB"` (required) |
| `burst` | Bytes sent at full speed first, such as `"10MiB"` (default: one second of `rate`) |
| `priority` | When it runs among the blocks of the location (default: `0`) |

Sizes are written as for [`body_limit`](/plugins/body-limit), with a unit: `B`, `KB`, `MB` (1,000 and 1,000,000 bytes), `KiB` or `MiB` (1,024 and 1,048,576 bytes).

### Usage

**config.hcl**
```hcl
host "downloads.example.com" {
  location "/files/" {
    static_files {
      directory = "/srv/files"
    }

    bandwidth_limit {
      rate  = "2MiB"
      burst = "20MiB"
    }
  }
}
```

Only some clients, with a [rule](/rules): here everyone but partners.

```hcl
host "downloads.example.com" {
  location "/files/" {
    static_files {
      directory = "/srv/files"
    }

    rule "everyone but partners" {
      and {
        not {
          client {
            in = ["198.51.100.0/24"]
          }
        }
      }
      then {
        bandwidth_limit {
          rate = "2MiB"
        }
      }
    }
  }
}
```

When a location and a rule both limit a response, the slower limit wins.

### Good to know

- Each location (and each rule) has its own limits, kept in memory on each Super server. They start over when the configuration changes.
- A client that stops downloading gets its `burst` back at `rate`, and costs no memory once it has.
- Clients are identified as for [`rate_limit`](/plugins/rate-limit): behind a proxy or load balancer, list it in `server.trusted_proxies`.
- Request bodies (uploads) aren't limited.