# OpenFileAsync(string)

> Opens the file asynchronously.

## Definition

* **Type:** Method
* **Namespace:** [Unity.IO.LowLevel.Unsafe](/engine/6000.5/script-reference/unity/io/lowlevel/unsafe.md)
* **Assembly:** UnityEngine.CoreModule

```csharp
public static FileHandle OpenFileAsync(string fileName)
```

### Parameters

**** (\[string]\(https\://learn.microsoft.com/dotnet/api/system.string)): The path to the file to be opened.

### Returns

| Type                                                                                 | Description                                                                                                                                               |
| ------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [FileHandle](/engine/6000.5/script-reference/unity/io/lowlevel/unsafe/filehandle.md) | The FileHandle of the file being opened. Use the FileHandle to check the status of the open operation, to read the file, and to close the file when done. |

### Remarks

**Note:** WebGL builds do not support using `AsyncReadManager` to open files from a remote web server; for example, from the path `Application.streamingAssetsPath` which maps to a URL on a remote web server.

### Examples

```csharp
using System.IO;
using Unity.IO.LowLevel.Unsafe;
using UnityEngine;

class AsyncOpenSample : MonoBehaviour
{
    FileHandle fileHandle;
    public unsafe void Start()
    {
        string filePath = Path.Combine(Application.streamingAssetsPath, "myfile.bin");

        fileHandle = AsyncReadManager.OpenFileAsync(filePath);
    }

    public unsafe void Update()
    {
        if (fileHandle.IsValid() && fileHandle.JobHandle.IsCompleted)
        {
            fileHandle.Close().Complete();
        }
    }
}
```