---
type: lookup
id: 4a-6f-79-21
asset: file-format-signatures
title: "4A 6F 79 21 — File format magic numbers"
sources:
  - https://en.wikipedia.org/wiki/List_of_file_signatures
source_quote: "<https://en.wikipedia.org/wiki/Preferred_Executable_Format> Preferred Executable Format"
generated: true
verified: false
harvested: 2026-08-03
stale_after: 2027-08-03
hex_signature: "4A 6F 79 21"
offset: "0"
format: "Preferred Executable Format"
unverified_fields: hex_signature, offset
---
**Hex signature:** 4A 6F 79 21

**Offset:** 0

**Format:** Preferred Executable Format

> <https://en.wikipedia.org/wiki/Preferred_Executable_Format> Preferred Executable Format

Source: <https://en.wikipedia.org/wiki/List_of_file_signatures>