---
title: "Find Files by Extension"
slug: "find-files-by-extension"
updated: 2025-09-02T19:57:12Z
published: 2025-09-02T19:57:12Z
canonical: "documentation.decisions.com/find-files-by-extension"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.decisions.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Find Files by Extension

| ## Step Details |
| --- |
| **Introduced in Version** | 4.0.0 |
| **Last Modified in Version** | 7.12.0 |
| **Location** | File Management |

The **Find Files With Extension** step lists all files in a directory with a similar extension.

---

## Properties

#### Inputs

| Property | Description | Data Type |
| --- | --- | --- |
| Extension | The string containing the extension name for a file. | String |
| Search Text | Searches the path of the directory for the file. | String |

#### Outputs

| Property | Description | Data Type |
| --- | --- | --- |
| Output | A List of File names which match the criteria list. | List of String |

![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1658256871313.png)

---

## Common Errors

### Index and length must refer to a location within the string

If the Length paired with the defined Start Index is longer than the length of the Input, the step will cause an error. To correct this, change the length or the starting index not to exceed the input's length.

#### Exception Message:

```csharp
Exception Stack Trace: DecisionsFramework.Design.Flow.ErrorRunningFlowStep: Error running step Substring 1[Substring] in flow [Display Steps]: Exception invoking method Substring on class StringSteps
 ---> DecisionsFramework.LoggedException: Exception invoking method Substring on class StringSteps
 ---> System.ArgumentOutOfRangeException: Index and length must refer to a location within the string. (Parameter 'length') 
   at System.String.Substring(Int32 startIndex, Int32 length)    
   --- End of inner exception stack trace --- 
   at DecisionsFramework.Design.Flow.StepImplementations.InvokeMethodStep.Run(StepStartData data
 at DecisionsFramework.Design.Flow.FlowStep.RunStepInternal(String flowTrackingID, String stepTrackingID, KeyValuePairDataStructure[] stepRunDataValues, AbstractFlowTrackingData trackingData) 
   at DecisionsFramework.Design.Flow.FlowStep.Start(String flowTrackingID, String stepTrackingID, FlowStateData data, AbstractFlowTrackingData trackingData, RunningStepData currentStepData)    
   --- End of inner exception stack trace ---
```