66 74 79 70 69 73 6F 6D

ISO Base Media file (MPEG-4) v1

category: file-signature
normalized: 6674797069736f6d
confirmed: 2026-03-15
lookups: 1
source: https://www.garykessler.net/

ISO Base Media file (MPEG-4) v1. File extension(s): MP4. Kessler type: Multimedia. Signature begins at byte offset 4.

Similar magic numbers

value	name	category
00 00 00 14 66 74 79 70 69 73 6F 6D	MPEG-4 v1	file-signature
66 74 79 70 6D 70 34 32	MPEG-4 video-QuickTime file	file-signature
66 74 79 70 33 67 70 35	MPEG-4 video file	file-signature
66 74 79 70 4D 53 4E 56	MPEG-4 video file	file-signature
66 74 79 70 4D 34 56 20	ISO Media-MPEG v4-iTunes AVC-LC	file-signature