---
title: "RegEx User Parameters"
description: "Configure the JMeter RegEx User Parameters pre processors: properties, defaults, and practical usage notes for building reliable load tests."
url: https://docs.jmeter.ai/components/regex-user-parameters/
lastUpdated: 2026-10-01
source: docs.jmeter.ai
---

# RegEx User Parameters

*Part of the **Pre Processors** category. Also documented in context in the [full Component Reference](/user-manual/component-reference/#regex-user-parameters).*

![RegEx User Parameters](/images/screenshots/regex_user_params.png)

Allows to specify dynamic values for HTTP parameters extracted from another HTTP Request using regular expressions.
RegEx User Parameters are specific to individual threads.

This component allows you to specify reference name of a regular expression that extracts names and values of HTTP request parameters.
Regular expression group numbers must be specified for parameter’s name and also for parameter’s value.
Replacement will only occur for parameters in the Sampler that uses this RegEx User Parameters which name matches

| Name | Required | Description |
| --- | --- | --- |
| Name | No | Descriptive name for this element that is shown in the tree. |
| Regular Expression Reference Name | Yes | Name of a reference to a regular expression |
| Parameter names regexp group number | Yes | Group number of regular expression used to extract parameter names |
| Parameter values regex group number | Yes | Group number of regular expression used to extract parameter values |

#### Regexp Example

Suppose we have a request which returns a form with 3 input parameters and we want to extract the value of 2 of them to inject them in next request

1. Create Post Processor Regular Expression for first HTTP Request          - `refName` - set name of a regular expression Expression (`listParams`) - `regular expression` - expression that will extract input names and input values attributes                          Ex: `input name="([^"]+?)" value="([^"]+?)"` - `template` - would be empty - `match nr` - `-1` (in order to iterate through all the possible matches)
2. Create Pre Processor RegEx User Parameters for second HTTP Request          - `refName` - set the same reference name of a regular expression, would be `listParams` in our example - `parameter names group number` - group number of regular expression for parameter names, would be `1` in our example - `parameter values group number` - group number of regular expression for parameter values, would be `2` in our example

See also the [Regular Expression Extractor](/components/regular-expression-extractor/) element, which is used to extract parameters names and values

#### See Also

- [Test Plan showing how to use RegEx User Parameters](../demos/RegEx-User-Parameters.jmx)

## Related

- [Correlation & Dynamic Values](/topics/correlation-dynamic-values/)
- [Regex Extractor Builder](/tools/regex-tester/)
- [Full Component Reference](/user-manual/component-reference/)
- [Functions and Variables](/user-manual/functions/)