We recommend using Visual Studio 2017
This documentation is archived and is not being maintained.

FileLen Function

Visual Studio 2008

Returns a Long value specifying the length of a file in bytes.

The My feature gives you greater productivity and performance in file I/O operations than FileLen. For more information, see My.Computer.FileSystem.GetFileInfo Method.

Public Function FileLen(ByVal PathName As String) As Long


Required. String expression that specifies a file. PathName may include the directory or folder, and the drive.

Exception type

Error number




File does not exist.

See the "Error number" column if you are upgrading Visual Basic 6.0 applications that use unstructured error handling. (You can compare the error number against the Number Property (Err Object).) However, when possible, you should consider replacing such error control with Structured Exception Handling Overview for Visual Basic.

If the specified file is open when the FileLen function is called, the value returned represents the size of the file at the time it was opened.


To obtain the current length of an open file, use the LOF function.

This example uses the FileLen function to return the length of a file in bytes. For purposes of this example, assume that TestFile is a file containing some data.

Dim MySize As Long 
' Returns file length (bytes).
MySize = FileLen("TESTFILE")

This function is not supported.

Namespace: Microsoft.VisualBasic

Module: FileSystem

Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)