JPEG signature (FF D8 FF)

file signature

magic: FF D8 FF⧉ copy @ offset 0

ascii: \xff\xd8\xff

trailer: FF D9

spec: ITU-T T.81 / ISO/IEC 10918-1

• FF D8 is the Start-of-Image (SOI) marker; the third byte FF begins the next marker segment.
• Common full prefixes: FF D8 FF E0 (JFIF APP0), FF D8 FF E1 (EXIF APP1), FF D8 FF DB (raw quantization table), FF D8 FF EE (Adobe).
• Stream ends with FF D9 (EOI), though appended thumbnails/metadata may follow.
• Within entropy-coded data a literal 0xFF byte is followed by 0x00 (byte stuffing) so it is not mistaken for a marker.

provenance

• source: https://www.w3.org/Graphics/JPEG/itu-t81.pdf
• version: ITU-T T.81 (JPEG), Table B.1 marker codes (SOI = 0xFFD8, EOI = 0xFFD9)
• retrieved: 2026-05-29 · updated: 2026-05-29T00:00:00Z

per-fact attribution:

• ext.magic_hex — https://www.w3.org/Graphics/JPEG/itu-t81.pdf SOI marker = 0xFFD8 starts the stream; EOI = 0xFFD9 ends it. The next marker (also 0xFF-led) follows SOI, giving the FF D8 FF prefix.
• ext.notes — https://en.wikipedia.org/wiki/JPEG_File_Interchange_Format Corroborates JFIF (FF E0) and EXIF (FF E1) APP marker following SOI, and the FF D8 FF E0 / FF D8 FF E1 / FF D8 FF DB common prefixes.

see also

• magic/png
• magic/gif