---
title: ".ico file — what it is and how to open it"
description: "A .ico file is a Windows Icon. A container holding one icon at several sizes, used by Windows and by website favicons. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/ico/
site: "At One Place"
---

# .ico files

**.ico file: Windows Icon**

A container holding one icon at several sizes, used by Windows and by website favicons.

## What opens a .ico file

- **Windows:** Photos (built in), IrfanView, GIMP, Paint (built in — single size only)
- **macOS:** Preview (built in), GIMP
- **Linux:** GIMP, Image Viewer / Loupe (built in)
- **In a browser:** Any web browser, favicon.io

## What a .ico file is

An ICO file bundles the same icon at multiple resolutions and colour depths so Windows can pick the right one for the desktop, the taskbar or a tooltip. Browsers use the same format for the little favicon in a tab, which is why /favicon.ico still exists on most sites. Windows Photos will display one, but making or editing icons needs a dedicated tool such as GIMP or an online generator.

## Converting it

A .ico file is commonly converted to .png, .svg, .icns or .bmp. It is a binary format, so a text editor will show unreadable characters rather than its contents.

## Details

- **Extension:** .ico
- **Full name:** Windows Icon
- **Category:** Images
- **MIME type:** image/vnd.microsoft.icon
- **Created by:** Microsoft
- **Format:** Binary

## Common questions

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

On Windows use Photos (built in); on macOS use Preview (built in); on Linux use GIMP. A container holding one icon at several sizes, used by Windows and by website favicons.

### What is a .ico file?

Windows Icon. An ICO file bundles the same icon at multiple resolutions and colour depths so Windows can pick the right one for the desktop, the taskbar or a tooltip. Browsers use the same format for the little favicon in a tab, which is why /favicon.ico still exists on most sites.

### Can I convert a .ico file?

Yes. It is usually converted to .png, .svg, .icns or .bmp, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.jpg — JPEG Image](https://atoneplace.net/file/jpg/)
- [.png — Portable Network Graphics](https://atoneplace.net/file/png/)
- [.jpeg — JPEG Image (four-letter form)](https://atoneplace.net/file/jpeg/)
- [.heic — High Efficiency Image Container](https://atoneplace.net/file/heic/)
- [.webp — WebP Image](https://atoneplace.net/file/webp/)
- [.gif — Graphics Interchange Format](https://atoneplace.net/file/gif/)
- [.psd — Adobe Photoshop Document](https://atoneplace.net/file/psd/)
- [.svg — Scalable Vector Graphics](https://atoneplace.net/file/svg/)
- [.ai — Adobe Illustrator Artwork](https://atoneplace.net/file/ai/)
- [.avif — AV1 Image File Format](https://atoneplace.net/file/avif/)
- [.tiff — Tagged Image File Format](https://atoneplace.net/file/tiff/)
- [.raw — Camera Raw Image](https://atoneplace.net/file/raw/)

## Sources

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