UI Automation activities

Last updated Jan 14, 2026

RegEx Search

About RegEx search

A regular expression, or RegEx, is a special text string for describing a search pattern. This makes them ideally suited for searching, text processing, and data validation. Using the RegEx search capabilities in selectors enables you to identify multiple target element with a single search execution. Without RegEx, multiple selectors would have been built to identify each target element.

How RegEx search works

To use the RegEx search capabilities, a matching option needs to be included in the tag of the element you want to identify, as follows:

Option	Description
`matching:<tag_name>=’regex’`	Allows you to specify the target search tag, determined by the `<tag_name>` value.
`<tag_name>='<regex_command>'`	Allows you to specify the search pattern through the `<regex_command>` expression used to identify the `<tag_name>`.

Supported selector types

Currently, the RegEx search is supported by the following selector types:

Selector type	Support
`<wnd>`	✅
`<html>`	✅
`<webctrl>`	✅
`<java>`	✅
`<ctrl>`	✅
`<uia>`	✅
`<sap>`	✅
Tags which identify a process name. Example: `<html app="firefox.exe">`.	❌

Examples of using RegEx search

Let's assume that we want to create an automation process which targets the Calculator application. However, for the purpose of this example, the value of the <name> tag alters between 0 and 2. Without the RegEx search, two selectors would have been built, one for each value of the <name> tag, as follows:

Selector for <name='Display is 0'> tag

<wnd app='applicationframehost.exe' appid='Microsoft.WindowsCalculator_8wekyb3d8bbwe!App' title='Calculator' />  <uia cls='LandmarkTarget' />  <uia automationid='CalculatorResults' name='Display is 0' role='text' />
<wnd app='applicationframehost.exe' appid='Microsoft.WindowsCalculator_8wekyb3d8bbwe!App' title='Calculator' />  <uia cls='LandmarkTarget' />  <uia automationid='CalculatorResults' name='Display is 0' role='text' />

Selector for the <name='Display is 2'> tag

<wnd app='applicationframehost.exe' appid='Microsoft.WindowsCalculator_8wekyb3d8bbwe!App' title='Calculator' />  <uia cls='LandmarkTarget' />  <uia automationid='CalculatorResults' name='Display is 2' role='text' />
<wnd app='applicationframehost.exe' appid='Microsoft.WindowsCalculator_8wekyb3d8bbwe!App' title='Calculator' />  <uia cls='LandmarkTarget' />  <uia automationid='CalculatorResults' name='Display is 2' role='text' />

Introducing RegEx search inside the second <uia> tag makes it possible to generate a single selector to match both cases. A valid selector, in this case, looks something like this:

<wnd app='applicationframehost.exe' appid='Microsoft.WindowsCalculator_8wekyb3d8bbwe!App' title='Calculator' /> 
<uia cls='LandmarkTarget' /> 
<uia automationid='CalculatorResults' name='Display is \d' role='text' matching:name='regex' />
<wnd app='applicationframehost.exe' appid='Microsoft.WindowsCalculator_8wekyb3d8bbwe!App' title='Calculator' /> 
<uia cls='LandmarkTarget' /> 
<uia automationid='CalculatorResults' name='Display is \d' role='text' matching:name='regex' />

The matching:name='regex' attribute instructs our selector to use RegEx to identify the <name> tag, while the <name='Display is \d'> command returns all the numerical values for the <name> tag it identifies.

Below are a couple of more examples on how RegEx search works and what values it returns:

Regular expression	Description	Returned results
`(.RPA.)\|(.Robotic Process Automation)`	Matches every string containing the RPA or Robotic Process Automation strings.	(...) leading RPA tool (...) UiPath is a Robotic Process Automation (...)
`^Index[0-5]`	Matches every string starting with the `Index` value, followed by any number between 0 and 5.	Index5 Index03