Free online VDI to VHDX converter

Source format

VDI is the virtual disk image format used primarily by Oracle VM VirtualBox. It stores the contents of a virtual machine’s hard drive, including the operating system, applications, and data. VDI files are common in VirtualBox-based labs, development environments, testing setups, and backups of virtual machines.

VDI can be either dynamically allocated or fixed-size, and it is designed to work best inside the VirtualBox ecosystem, though it can be converted for use in other hypervisors.

Target format

VHDX is Microsoft’s newer virtual hard disk format, used mainly by Hyper-V and other Microsoft virtualization tools. Compared with older VHD, VHDX supports much larger disks, better resilience against corruption, and improved performance characteristics. It is commonly used for Windows Server, Hyper-V virtual machines, and enterprise virtualization workloads.

VHDX is a good target when moving a virtual machine from VirtualBox to Hyper-V or when you need a Microsoft-native virtual disk format for compatibility with Windows virtualization platforms.

How to perform the conversion

The most reliable method is to use VirtualBox’s built-in disk conversion tool, VBoxManage, which can convert a VDI disk into a VHD file. Because VHDX is not always directly supported as an export target by VirtualBox, the usual workflow is to convert VDI → VHD first, then convert VHD → VHDX using Microsoft tools or Hyper-V utilities.

Step 1: Locate the source VDI file
Make sure the virtual machine is powered off and the disk is not in use. Find the .vdi file associated with the VM.

Step 2: Convert VDI to VHD with VBoxManage
Open a terminal or command prompt and run a command similar to:

VBoxManage clonemedium disk source.vdi target.vhd --format VHD

This creates a VHD copy of the VirtualBox disk. If your VirtualBox version uses older syntax, the equivalent command may be:

VBoxManage clonehd source.vdi target.vhd --format VHD

Step 3: Convert VHD to VHDX
Use Hyper-V Manager or PowerShell on Windows to convert the VHD into VHDX. In PowerShell, the Convert-VHD cmdlet is commonly used:

Convert-VHD -Path target.vhd -DestinationPath target.vhdx -VHDType Dynamic

If you prefer the graphical interface, open Hyper-V Manager → Edit Disk and follow the wizard to convert the disk to VHDX.

Step 4: Attach the VHDX to a Hyper-V virtual machine
After conversion, create or configure a Hyper-V VM and attach the new .vhdx file as its virtual hard disk.

If you only need a quick conversion and do not want to install software, you can convert the file on 101convert.com for free, without installing any software.

Notes on quality, compatibility, or limitations

Disk conversion preserves data, but it does not guarantee that the guest operating system will boot in the new hypervisor without adjustments. VirtualBox and Hyper-V use different virtual hardware, so you may need to reinstall guest tools, update storage drivers, or repair boot settings.

VHDX is not supported by older Windows versions and is intended for newer Hyper-V environments. If you need compatibility with legacy systems, plain VHD may be a better choice.

Also note that dynamic vs. fixed allocation can affect file size and performance. When converting, choose the VHDX type that matches your deployment needs. For best results, keep a backup of the original VDI before converting.