Free online IMG to QCOW2 converter

Source format

IMG is a broad disk image format name rather than a single strict standard. In practice, an .img file usually contains a raw byte-for-byte copy of a disk, partition, or removable media. It is commonly used by system administrators, embedded-device users, and forensic tools to store bootable media, SD cards, USB drives, or full virtual disks. Because IMG can represent different internal layouts, the exact contents may vary from one file to another.

Target format

QCOW2 is the QEMU Copy On Write version 2 virtual disk format used by QEMU, KVM, and many virtualization platforms. It supports features such as copy-on-write, snapshots, optional compression, and thin provisioning, which can save storage compared with a raw image. QCOW2 is a strong choice for virtual machines because it is flexible, efficient, and widely supported in Linux-based virtualization workflows.

How to perform the conversion

The best tool for this conversion is usually qemu-img, which is included with QEMU and is designed specifically for disk image conversion.

1. Install QEMU tools if they are not already present. On Linux, this is often provided by a package such as qemu-utils or qemu-img.
2. Open a terminal in the folder containing your source image.
3. Run a conversion command such as qemu-img convert -f raw -O qcow2 source.img target.qcow2.
4. If the source image is not a raw disk image, specify the correct input format with -f. For example, some .img files may actually be VMDK, VDI, or another format despite the extension.
5. After conversion, verify the result with qemu-img info target.qcow2.

If you prefer a graphical workflow, some virtualization tools and disk utilities can open or import raw images and save them as QCOW2, but qemu-img is usually the most reliable and precise method. You can also convert the file on 101convert.com for free, without installing any software.

Notes on quality, compatibility, or limitations

The main limitation is that IMG is ambiguous: the conversion only works correctly if you know the image’s real format and structure. If the file is a raw disk image, conversion is straightforward and usually lossless. If the image contains a partition table, boot sector, or full disk layout, those structures are preserved in QCOW2 because the conversion copies the disk blocks rather than changing the filesystem itself.

Keep in mind that QCOW2 is ideal for virtualization, but it is not the best choice if you need a simple byte-for-byte archival copy for non-virtualization tools. Also, some guest operating systems or hypervisors may perform better with raw images than with QCOW2, especially in high-throughput scenarios. If the source image is compressed, encrypted, or damaged, conversion may fail or produce an unusable VM disk.