All file extensions
.ICO File
What is it?
ICO is the icon format used by Windows for application and file icons, and by websites as favicons — it can bundle multiple image sizes in one file.
How do I open it?
Windows displays ICO files as icons automatically; image editors and dedicated icon viewers can open them directly.
Is it safe?
Yes, ICO only stores image data.
Can I delete it?
Safe to delete standalone ICO files; don't delete one that's actively used as an app's icon file, or the app may show a broken or default icon.