Icon File — Windows icon format storing multiple sizes and color depths.
Quick facts
What is .ico
A .ico file is a Icon File — Windows icon format storing multiple sizes and color depths.
In the mime-db registry it maps to image/vnd.microsoft.icon, and it is marked as compressible. When serving .ico over HTTP, set the Content-Type header as shown in Developer info below.
Related entities: it maps to image/vnd.microsoft.icon — and is delivered over HTTP via the Content-Type header.
How to open .ico files
Developer info
When served over HTTP, responses should set the following header:
Content-Type: image/vnd.microsoft.icon
Common software that reads/writes .ico:
Relation chain
Related extensions
Related MIME types
Common uses
How to edit .ico files
How to create .ico files
Frequently asked questions
Common options include IcoFX, GIMP, Windows. You can also open many of these files with built-in viewers or a browser.
Create a new file in any text editor or the app that owns the format and save it with the .ico extension.
image/vnd.microsoft.icon is the media type identifier used for .ico files during network transfer (for example in the HTTP Content-Type header).
Sources & standards
Updated 2026-08-18
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