Magic Numbers

File type

Hex signature in start of file

MIME type

jpeg

ff d8 ff

image/jpeg

png

89 50 4e 47

image/png

bz2

42 5a 68

application/octet-stream

gif

47 49 46 38 37 61

image/gif

gif

47 49 46 38 39 61

image/gif

zip jar apk docx ipa pptx xlsx

50 4b 03 04

application/octet-stream

Java class

ca fe ba be

application/octet-stream

tar

75 73 74 61 72

application/octet-stream

gzip

1f 8b

application/octet-stream