What is a .ico file?
A .ico file is a windows icon. Its registered MIME type is image/vnd.microsoft.icon, which places it in the image family of formats.
ICO is a binary format: the contents are not readable text, so opening it in a text editor shows scrambled characters.
Files of this type usually begin with the bytes 00 00 01 00. That signature is how programs recognise the format even when the extension is wrong or missing.
ICO file format details
| Extension | .ico |
|---|---|
| Format | Windows icon |
| MIME type | image/vnd.microsoft.icon, image/x-icon, application/ico |
| Category | Image |
| Text or binary | Binary |
| File signature | 00 00 01 00 |
| Registered with IANA | Yes |
| Other extensions | None |
How to open ICO files
| Windows | The Photos app and every web browser display this format. |
|---|---|
| Mac | Preview opens most image formats. If it cannot, a dedicated image editor usually can. |
| iPhone and iPad | Photos and the Files app show common image types. Less common ones may need an app, or conversion to JPG or PNG. |
| Android | Google Photos and gallery apps show common images. Other formats may need a viewer app. |
Convert ICO files
TapToConvert converts ICO files in your browser, without uploading them. Open the ICO converter, or go straight to a conversion:
ICO file FAQ
What is a .ico file?
A .ico file is a windows icon, with the MIME type image/vnd.microsoft.icon.
How do I open a .ico file?
With the program that created it. The viewer on this page shows what is inside without installing anything.
Is a .ico file safe to open?
ICO files hold data rather than programs, but any file from an unknown source can be crafted to exploit the software that opens it. Keep that software up to date. The viewer on this page only reads the bytes and never runs anything.
What is the MIME type of .ico?
image/vnd.microsoft.icon, and it is also seen as image/x-icon or application/ico. Web servers send this type so browsers know how to handle the file.
Is ICO a text or binary format?
Binary. Its contents are not readable as text.
File type facts come from the IANA media type registry, the mime-db project and the freedesktop.org shared MIME database.