SoftNexi

Windows · Backup & Disk Imaging

Win32 Disk Imager for Windows

Simple open-source Windows tool for writing raw disk image files to SD cards and USB drives, and for reading a drive back into an image file.

Updated August 9, 2026 · Reviewed by SoftNexi Editorial Team, Software research and documentation

Download

Overview

Win32 Disk Imager is a minimal, no-frills utility that does two things: write a raw .img file to a removable drive, and read a removable drive back into a raw .img file. It predates newer tools like balenaEtcher and Ventoy and remains popular specifically in the Raspberry Pi and embedded-Linux community for preparing SD card images.

It has essentially no extra features beyond that core read/write function — no image library, no verification wizard beyond an optional checksum, no Windows installer-specific options. That simplicity is the appeal for users who just need a dependable, lightweight img writer without a modern UI wrapped around it.

Because it works with any drive letter Windows assigns, including SD card readers, it's a common companion tool for single-board computer projects rather than for Windows installation media, where Rufus or balenaEtcher's added polish is more commonly reached for.

Development has been slow in recent years since the tool does not need much ongoing work to do its narrow job well, but that also means don't expect frequent interface updates.

Key features

  • Writes raw .img files to a target drive
  • Reads a drive back into a raw .img file for backup or duplication
  • Optional MD5 hash calculation for verifying an image
  • Minimal, lightweight interface with no unnecessary extras
  • Open-source codebase available for review

System requirements

Operating system
Windows 11 and Windows 10 (older Windows releases also supported)
Target media
USB drives and SD cards accessible via a drive letter
Permissions
Administrator rights required to write to a drive

How to install Win32 Disk Imager

  1. 1. Download from SourceForge

    Get the installer from the official Win32 Disk Imager project page.

  2. 2. Install

    Run the installer with default options.

  3. 3. Insert your target media

    Insert the SD card or USB drive you intend to write to or read from before launching the tool.

How to use it

  1. 1. Write an image to a drive

    Select the .img file, confirm the correct target drive letter, and click Write.

  2. 2. Read a drive into an image file

    Choose a destination file name, select the source drive, and click Read to create a raw backup of that drive's contents.

  3. 3. Verify with the hash option

    Use the built-in MD5 calculation to confirm a downloaded or created image matches its expected hash.

Safety and privacy

  • Download only from the project's official SourceForge page; SourceForge itself hosts many bundled-installer projects, so confirm you're on the correct project page.
  • Writing an image overwrites the target drive completely — verify drive selection before starting.
Bundled software
The project's own installer does not bundle third-party offers, but always confirm you're downloading from the correct official project listing given SourceForge's mixed reputation for other projects.
Privacy
Runs entirely locally with no account or network requirement.

Known risks

  • As with any raw disk writer, selecting the wrong target drive will erase it without an undo option.

What's new

  • Current release

    Win32 Disk Imager sees infrequent updates given its narrow scope. Check the project's SourceForge page for the current release.

Pros and cons

Pros

  • Extremely simple and lightweight
  • Free and open source
  • Works well for SD card imaging in Raspberry Pi and embedded projects
  • Includes basic hash verification

Cons

  • No modern interface polish compared to balenaEtcher
  • No Windows installer-specific features
  • Infrequent updates given its narrow scope

Verdict

Win32 Disk Imager remains a dependable, no-nonsense choice for raw image writing and reading, particularly in the Raspberry Pi and embedded-Linux world. For general ISO flashing with a more modern interface, balenaEtcher is worth trying instead.

Frequently asked questions

Is Win32 Disk Imager free?

Yes, it's free and open source.

Can it back up an SD card, not just write to one?

Yes, its Read function creates a raw image file from a drive, which can serve as a backup or duplication source.

Is it better than balenaEtcher?

It's simpler and more narrowly focused. balenaEtcher offers a more modern interface and automatic write verification; both write raw images reliably.