Windows cursor file signature
Magic number at the start of the file
A Windows cursor uses the icon header with the image type set to 2: 00 00 02 00. An icon (.ico) uses 00 00 01 00 in the same position.
What this magic number means
A magic number is a short, fixed run of bytes at a known position that tells a program what a file really is, no matter what the filename says. If a file starts with the bytes 00 00 02 00, it is a Windows cursor file.
Formats that use the 00 00 02 00 signature
These file types in our database carry this signature:
How to check a file's signature
You can read the first bytes of any file yourself. The magic bytes are shown in hex, the same way this page lists them.
Linux & macOS
- xxd -l 16 example.cur
- hexdump -C -n 16 example.cur
- file example.cur
Windows (PowerShell)
- Format-Hex -Path example.cur -Count 16
Python
- open("example.cur","rb").read(4).hex()
In your browser
- Drop the file into the WhatFileType identifier, which reads the signature without uploading it.
Frequently asked questions
What is the Windows cursor file signature?
Windows cursor files start with the hex bytes 00 00 02 00. This magic number identifies the format regardless of the file's name or extension.
How do I check a file's magic number?
Open the file in a hex editor, or run a command such as xxd -l 16 example.cur on Linux or macOS, or Format-Hex -Path example.cur -Count 16 in Windows PowerShell, and read the first bytes.
Can a file fake the Windows cursor signature?
Renaming a file does not change its bytes, so the extension can lie but the signature usually cannot. A genuine Windows cursor file has these exact bytes; a file with the wrong bytes is not really Windows cursor, whatever its name says.