Compact WSL Disk Image unused space

December 22, 2025

Windows Subsystem for Linux (WSL) uses VHDX files to store each distribution’s filesystem. Over time these disk images grow in size as files are added and deleted. However, the space used by deleted files is not automatically reclaimed, leading to larger disk images than necessary.

There is a PowerShell script to automatically compact WSL VHDX files that works with any of the Windows release levels (including Home).