MOV file signature
Magic number at offset 4 · ftypqt
A QuickTime MOV is an ISO Base Media file whose ftyp box declares the brand qt (with trailing spaces) at offset 8. Some older MOV files instead begin directly with a moov or mdat box.
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 contains, at offset 4, the bytes 66 74 79 70 71 74 20 20 (the text ftypqt ), it is a MOV file.
Formats that use the 66 74 79 70 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 -s 4 -l 8 example.mov
- hexdump -C -s 4 -n 8 example.mov
- file example.mov
Windows (PowerShell)
- Format-Hex -Path example.mov -Count 16
Python
- f=open("example.mov","rb");f.seek(4);f.read(8).hex()
In your browser
- Drop the file into the WhatFileType identifier, which reads the signature without uploading it.
Frequently asked questions
What is the MOV file signature?
MOV files carry, at offset 4, the hex bytes 66 74 79 70 71 74 20 20 (ftypqt in ASCII). 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.mov on Linux or macOS, or Format-Hex -Path example.mov -Count 16 in Windows PowerShell, and read the first bytes.
Can a file fake the MOV signature?
Renaming a file does not change its bytes, so the extension can lie but the signature usually cannot. A genuine MOV file has these exact bytes; a file with the wrong bytes is not really MOV, whatever its name says.