# MPEG-4 video file — file signature 66 74 79 70 4D 53 4E 56 at offset 4

For MPEG-4 video file, hex signature is 66 74 79 70 4D 53 4E 56; extension is mp4, verified against its source on 2026-09-22.

- **Hex signature:** 66 74 79 70 4D 53 4E 56 _(verified: appears in the quote below)_
- **Offset:** 4 _(verified: appears in the quote below)_
- **Extension:** mp4 _(verified: appears in the quote below)_
- **Format:** MPEG-4 video file _(verified: appears in the quote below)_

## What the source says

> 66 74 79 70 4D 53 4E 56 | ftypMSNV | 4 | mp4 | MPEG-4 video file |

## Source

- https://en.wikipedia.org/wiki/List_of_file_signatures

Last verified: 2026-09-22. Review by: 2027-09-22.
Part of [File format magic numbers](https://referencesource.org/file-format-signatures/).