Skip to content
>_ FileDex █

>_ Convert Your File

DROP SPECIMEN HERE

Accepted: ICO :: Max 500MB
[SECURE] :: No files transmitted to external hosts
┌─ FILE ANALYSIS ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── ┐
│ DEVELOPER : Microsoft
│ CATEGORY : Image
│ MIME TYPE : image/x-icon
│ MAGIC BYTES : 00000100
└ ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── ┘

What is an ICO file?

ICO is an image format used for icons in Microsoft Windows. An ICO file can contain multiple images at different sizes and color depths, allowing Windows to select the most appropriate version for each display context (taskbar, desktop, file explorer).

How to open ICO files

  • Windows — Native support (displayed as icons)
  • Any web browser — Used as favicons
  • GIMP (Windows, macOS, Linux) — Free, can edit ICO files
  • IcoFX (Windows) — Dedicated icon editor
  • Greenfish Icon Editor (Windows) — Free icon editor

Technical specifications

PropertyValue
Multi-sizeUp to 256×256 pixels per image
Color Depth1-bit to 32-bit (with alpha)
FormatBMP or PNG compressed frames
TransparencyFull alpha channel (32-bit)
Multi-imageMultiple sizes in one file

Programs that open ICO files

  • IcoFX — Professional icon editor
  • Greenfish Icon Editor Pro — Free icon editor
  • GIMP — Import/export ICO format
  • RealWorld Icon Editor — Free Windows tool
  • Favicon.io — Online ICO generator

Common use cases

  • Application icons: Windows executable icons
  • Favicons: Website tab icons (favicon.ico)
  • File associations: Custom file type icons
  • Shortcuts: Desktop and taskbar shortcuts