---
title: ".iso file — what it is and how to open it"
description: "A .iso file is an ISO Disc Image. A byte-for-byte copy of a CD, DVD or installer disc in one file. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/iso/
site: "At One Place"
---

# .iso files

**.iso file: ISO Disc Image**

A byte-for-byte copy of a CD, DVD or installer disc in one file.

## What opens a .iso file

- **Windows:** File Explorer (built in — right-click > Mount), 7-Zip, Rufus (to write to USB)
- **macOS:** DiskImageMounter (built in), Disk Utility (built in), balenaEtcher
- **Linux:** Disk Image Mounter (built in), mount -o loop, balenaEtcher

## What a .iso file is

An ISO holds an entire optical disc filesystem, which is why operating systems are distributed this way. Windows 10 and 11 mount one as a drive letter from the right-click menu, macOS mounts it on double-click, and Linux desktops offer Disk Image Mounter. To install from it you usually want to write it to a USB stick with Rufus, balenaEtcher or Startup Disk Creator rather than just copying the file across.

## Converting it

A .iso file is commonly converted to .img, .dmg, .zip or .usb. It is a binary format, so a text editor will show unreadable characters rather than its contents.

## Details

- **Extension:** .iso
- **Full name:** ISO Disc Image
- **Category:** Disk images
- **MIME type:** application/x-iso9660-image
- **Created by:** ISO 9660 standard
- **Format:** Binary

## Common questions

### How do I open a .iso file?

On Windows use File Explorer (built in — right-click > Mount); on macOS use DiskImageMounter (built in); on Linux use Disk Image Mounter (built in). A byte-for-byte copy of a CD, DVD or installer disc in one file.

### What is a .iso file?

ISO Disc Image. An ISO holds an entire optical disc filesystem, which is why operating systems are distributed this way. Windows 10 and 11 mount one as a drive letter from the right-click menu, macOS mounts it on double-click, and Linux desktops offer Disk Image Mounter.

### Can I convert a .iso file?

Yes. It is usually converted to .img, .dmg, .zip or .usb, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.dmg — Apple Disk Image](https://atoneplace.net/file/dmg/)
- [.vmdk — Virtual Machine Disk](https://atoneplace.net/file/vmdk/)
- [.cue — Cue Sheet](https://atoneplace.net/file/cue/)

## Sources

- Media Types Registry — IANA (https://www.iana.org/assignments/media-types/)
- Official vendor product documentation — At One Place (/about/)