.img

What is a .img file?

IMG is a raw sector-by-sector disk image — an exact copy of a disk's contents including boot sectors and partitions.

Use caution
Type System
By Generic format (no single creator)
MIME application/octet-stream

Drop any file to identify it

No upload. No signup. No sending your file halfway across the internet.
We tell you what it is, right here in your browser.

What is it

An .img file is the simplest possible disk image: a byte-for-byte copy of a disk's contents, from the first sector to the last. No compression, no metadata, no container format — just raw data in the exact order it appears on the physical disk. Raspberry Pi OS distributions, firmware images, and forensic disk captures all use .img.

The format is used for writing bootable media: `dd if=image.img of=/dev/sdX` on Linux, or Raspberry Pi Imager on any platform, writes the image directly to an SD card or USB drive. The result is a bootable disk identical to the original. This is why OS distributions for embedded devices (Raspberry Pi, routers, single-board computers) ship as .img files.

On Windows, Win32 Disk Imager or Rufus write .img files to USB drives. On Mac, `dd` or Etcher handle it. The files can be large (matching the original disk size) but compress well since unused disk space is typically zeroes.

Technical details
Full Name
Disk Image
MIME Type
application/octet-stream
Developer
Generic format (no single creator)
Magic Bytes
N/A
Safety
.img requires caution. Disk images can contain any data including bootable operating systems. Writing to a USB drive overwrites all existing data on that drive.
What opens it
Raspberry Pi Imager
FREE Windows / Mac / Linux
Etcher
FREE Windows / Mac / Linux
dd (CLI)
FREE Mac / Linux
FAQ
How do I write an IMG file to a USB drive?
Use Raspberry Pi Imager (easiest), Etcher, or Rufus (Windows). On Linux/Mac: `sudo dd if=image.img of=/dev/sdX bs=4M status=progress`. Warning: this overwrites everything on the target drive.
Can I mount an IMG file to see its contents?
On Linux: `sudo mount -o loop image.img /mnt/img`. On Mac: `hdiutil attach image.img`. On Windows: use OSFMount (free) or WSL.
Related formats