---
title: "HTTP Mirror Server"
description: "Configure the JMeter HTTP Mirror Server miscellaneous features: properties, defaults, and practical usage notes for building reliable load tests."
url: https://docs.jmeter.ai/components/http-mirror-server/
lastUpdated: 2026-10-01
source: docs.jmeter.ai
---

# HTTP Mirror Server

*Part of the **Miscellaneous Features** category. Also documented in context in the [full Component Reference](/user-manual/component-reference/#http-mirror-server).*

![HTTP Mirror Server](/images/screenshots/mirrorserver.png)

The HTTP Mirror Server is a very simple HTTP server - it simply mirrors the data sent to it.
This is useful for checking the content of HTTP requests.

It uses default port `8081`.

| Name | Required | Description |
| --- | --- | --- |
| Port | Yes | Port on which Mirror server listens, defaults to `8081`. |
| Max Number of threads | No | If set to a value > `0`, number of threads serving requests will be limited to the configured number, if set to a value ≤ `0`         a new thread will be created to serve each incoming request. Defaults to `0` |
| Max Queue size | No | Size of queue used for holding tasks before they are executed by Thread Pool, when Thread pool is exceeded, incoming requests will         be held in this queue and discarded when this queue is full. This parameter is only used if Max Number of Threads is greater than `0`. Defaults to `25` |

> **Note**
> Note that you can get more control over the responses by adding an HTTP Header Manager with the following name/value pairs:

| Name | Required | Description |
| --- | --- | --- |
| X-Sleep | No | Time to sleep in ms before sending response |
| X-SetCookie | No | Cookies to be set on response |
| X-ResponseStatus | No | Response status, see [HTTP Status responses](http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html), example 200 OK, 500 Internal Server Error, …. |
| X-ResponseLength | No | Size of response, this trims the response to the requested size if that is less than the total size |
| X-SetHeaders | No | Pipe separated list of headers, example:         `headerA: valueA |

You can also use the following query parameters:

| Name | Required | Description |
| --- | --- | --- |
| redirect | No | Generates a 302 (Temporary Redirect) with the provided location,     e.g. `?redirect=/path` |
| status | No | Overrides the default status return, e.g. `?status=404 Not Found` |
| v | No | Verbose flag, writes some details to standard output, e.g. first line and redirect location if specified |

## Related

- [Plugins Essentials](/topics/plugins-essentials/)
- [Full Component Reference](/user-manual/component-reference/)
- [Functions and Variables](/user-manual/functions/)