Free online VHD to QCOW2 converter

Source format: vhd

VHD (Virtual Hard Disk) is a disk image format originally associated with Microsoft virtualization products such as Virtual PC, Hyper-V, and some backup or disk management tools. A VHD file stores the contents of a virtual hard drive, including partitions, file systems, and operating system data. It is commonly used for virtual machines, system migration, testing, and archival of bootable disks.

VHD exists in fixed and dynamically expanding variants. It is widely recognized in Windows-centric environments, but support also exists in many virtualization platforms and conversion tools.

Target format: qcow2

QCOW2 is the second version of the QEMU Copy On Write disk image format, used primarily with QEMU and KVM virtualization. It is a flexible virtual disk format that supports snapshots, copy-on-write, compression, and sparse allocation. These features make it a strong choice for Linux-based virtualization workflows and advanced VM management.

Compared with VHD, qcow2 is often preferred in QEMU/KVM environments because it offers better support for snapshots and efficient storage usage. It is a common format for VM deployment, testing, and migration between virtualization hosts.

How to perform the conversion

The most reliable desktop tool for converting VHD to qcow2 is qemu-img, which is included with QEMU on most platforms.

1. Install QEMU tools if they are not already available. On Linux, this is often provided by a package such as qemu-utils or qemu-img. On Windows and macOS, install a QEMU package that includes qemu-img.
2. Open a terminal or command prompt.
3. Run the conversion command:
   qemu-img convert -f vpc -O qcow2 input.vhd output.qcow2
4. If needed, verify the result with:
   qemu-img info output.qcow2

In this command, -f vpc tells QEMU to read the source as a VHD file, because QEMU uses vpc as the input format name for VHD. -O qcow2 sets the output format to qcow2.

If you prefer a graphical workflow, you can also use virtualization management tools that support disk conversion, but qemu-img is usually the simplest and most dependable option for this specific conversion. You can also convert the file on 101convert.com website for free, without installing any software.

Notes on quality, compatibility, or limitations

Disk conversion does not repair filesystem problems. If the VHD is corrupted, the qcow2 output will usually preserve those issues. It is best to work from a healthy source image.

Partition and boot compatibility depend on the guest operating system and firmware settings. After conversion, a VM may still need the correct BIOS/UEFI mode, storage controller, or bootloader configuration to start successfully.

Dynamic vs. fixed size behavior may change during conversion. qcow2 is typically sparse and grows as data is written, which can reduce initial storage usage.

Performance can differ from VHD, especially if snapshots or compression are used. qcow2 is feature-rich, but raw performance may be slightly lower than simpler disk formats in some workloads.

For best results, shut down the virtual machine before copying or converting the disk image, and keep a backup of the original VHD until the qcow2 image has been tested.