Your hex editor should color-code bytes

alice pellerin • 2026-03-31

too often, i see hex editors1 that look like this:

00000000 00 00 02 00 28 00 00 00 88 15 00 00 C4 01 00 00 ⋄⋄•⋄(⋄⋄⋄ו⋄⋄ו⋄⋄
00000010 14 00 00 00 03 00 00 00 00 01 00 00 03 00 00 00 •⋄⋄⋄•⋄⋄⋄⋄•⋄⋄•⋄⋄⋄
00000020 3C 00 00 00 C4 0A 00 00 50 00 00 00 18 00 00 00 <⋄⋄⋄×⏎⋄⋄P⋄⋄⋄•⋄⋄⋄
00000030 14 00 00 10 00 00 00 00 18 00 00 20 00 00 00 00 •⋄⋄•⋄⋄⋄⋄•⋄⋄ ⋄⋄⋄⋄
00000040 20 00 00 30 00 00 00 00 51 00 00 00 48 00 00 00 ⋄⋄0⋄⋄⋄⋄Q⋄⋄⋄H⋄⋄⋄
00000050 10 00 00 80 00 00 00 00 00 00 00 A0 00 00 00 00 •⋄⋄×⋄⋄⋄⋄⋄⋄⋄×⋄⋄⋄⋄
00000060 01 00 00 A0 01 00 00 00 02 00 00 A0 02 00 00 00 •⋄⋄ו⋄⋄⋄•⋄⋄ו⋄⋄⋄
00000070 03 00 00 A0 03 00 00 00 04 00 00 A0 04 00 00 00 •⋄⋄ו⋄⋄⋄•⋄⋄ו⋄⋄⋄
00000080 05 00 00 A0 05 00 00 00 06 00 00 A0 06 00 00 00 •⋄⋄ו⋄⋄⋄•⋄⋄ו⋄⋄⋄
00000090 20 00 00 30 00 00 00 00 53 00 00 00 00 DE 00 00 ⋄⋄0⋄⋄⋄⋄S⋄⋄⋄⋄×⋄⋄
000000a0 5D FA 01 44 E1 3A 9A 0F 52 00 00 00 FC 14 00 00 ]וD×:וR⋄⋄⋄ו⋄⋄
000000b0 1B 20 2A 2B 00 80 00 00 00 80 00 00 00 80 00 00 • *+⋄×⋄⋄⋄×⋄⋄⋄×⋄⋄
000000c0 FF 7F 00 00 00 00 33 52 00 00 00 00 29 10 15 10 ╳•⋄⋄⋄⋄3R⋄⋄⋄⋄)•••
000000d0 80 00 1F 00 03 00 00 00 02 00 00 00 40 14 22 23 ×⋄•⋄•⋄⋄⋄•⋄⋄⋄@•"#
000000e0 03 00 00 00 06 00 00 00 23 00 9D 05 6B FA C0 05 •⋄⋄⋄•⋄⋄⋄#⋄וk×ו
000000f0 C8 03 00 00 14 22 23 14 05 00 00 00 2E 00 9E 06 ו⋄⋄•"#••⋄⋄⋄.⋄ו

every time i do, i feel bad for the poor person having to use it (especially if that person is me!). a plain list of bytes makes it hard to notice interesting things in the data. go ahead, try to find the single C0 in these bytes:

00000000 15 29 21 25 03 2F 2E 2B 15 11 24 3F 10 14 3B 13 •)!%•/.+••$?••;•
00000001 32 25 09 01 10 02 01 23 26 1E 25 2D 24 2F 23 3E 2%␣••••#&•%-$/#>
00000002 05 0F 33 2D 18 29 3E 1E 16 3B 29 0D 24 0B 3E 38 ••3-•)>••;)␍$•>8
00000003 33 3C 1E 2C 28 31 C0 1D 11 32 14 05 10 17 3F 01 3<•,(1ו•2••••?•
00000004 1E 32 0A 14 2B 2F 0B 14 3E 27 39 0A 17 23 1B 39 •2⏎•+/••>'9⏎•#•9
00000005 18 0B 3B 13 25 14 2C 3B 33 3C 19 10 21 0F 2C 34 ••;•%•,;3<••!•,4
00000006 2F 0C 1D 2C 2E 22 11 28 0D 0A 1F 37 27 39 35 21 /••,."•(␍⏎•7'95!
00000007 23 39 21 2B 37 23 28 16 30 28 02 04 25 22 37 1F #9!+7#(•0(••%"7•
00000008 36 2F 2D 25 12 25 01 31 3B 39 2D 35 26 37 30 2A 6/-%•%•1;9-5&70*
00000009 06 0D 11 1F 25 0A 1E 29 15 0B 0A 2A 2E 2C 21 16 •␍••%⏎•)••⏎*.,!•
0000000a 1D 37 0F 16 12 03 2C 02 0B 22 24 11 1A 3B 0D 0B •7••••,••"$••;␍•
0000000b 0D 13 30 2D 3B 15 05 15 32 19 20 30 3C 0E 3D 0B ␍•0-;•••2• 0<•=•
0000000c 17 24 22 3E 1E 22 18 0D 21 06 29 38 3E 20 3B 12 •$">•"•␍!•)8> ;•
0000000d 06 1F 19 17 29 35 1E 3B 1E 01 31 08 13 0C 27 20 ••••)5•;••1•••' 
0000000e 08 24 2E 32 16 06 1F 3D 35 35 19 16 02 07 31 13 •$.2•••=55••••1•
0000000f 31 33 30 36 14 32 07 05 05 34 19 0B 18 16 12 3C 1306•2•••4•••••<

compare that to one with colors:

00000000 37 2D 08 13 0D 0B 18 1D 02 1A 2D 12 2A 0D 0F 27 7-••␍•••••-•*␍•'
00000001 04 2A 25 32 0F 17 32 11 2F 2A 2A 0A 0A 16 04 1D •*%2••2•/**⏎⏎•••
00000002 32 13 09 01 2B 26 1A 30 3D 26 13 39 09 0D 38 3E 2•␣•+&•0=&•9␣␍8>
00000003 0A 0D 1D 0B 36 30 02 36 0E 0B 2F 09 26 1E 33 03 ⏎␍••60•6••/␣&•3•
00000004 3C 3C 08 0A 1E 36 12 11 1B 17 05 09 0B 37 0C 0E <<•⏎•6•••••␣•7••
00000005 31 05 09 17 2D 1D 05 16 25 03 3E 0A 1A 01 0C 2B 1•␣•-•••%•>⏎•••+
00000006 13 37 17 14 37 03 18 34 2D 03 30 11 2B 19 04 0B •7••7••4-•0•+•••
00000007 04 2A 18 26 21 25 3F 23 1D 0F 2F 2B 35 0C 09 37 •*•&!%?#••/+5•␣7
00000008 25 33 19 1C 12 1E 2E 38 3A 3A 3C 28 39 0A 30 23 %3••••.8::<(9⏎0#
00000009 21 08 09 24 0B 0E 13 26 04 30 06 20 10 18 15 3C !•␣$•••&•0• •••<
0000000a 10 3C 30 34 28 28 1D 31 22 23 22 38 0E 12 25 15 •<04((•1"#"8••%•
0000000b 3B 1F 30 0D 26 0E 15 32 1C 2B 12 1A 32 1C 02 07 ;•0␍&••2•+••2•••
000000c0 35 2E 06 13 1F 33 3D 16 05 1C 2A 0F 34 34 21 26 5.•••3=•••*•44!&
000000d0 0C 17 3D 02 27 39 21 17 3F 07 1A 2F 38 0D 2D 1E ••=•'9!•?••/8␍-•
000000e0 32 0C C0 14 0E 20 25 0E 2E 2D 0D 21 27 13 2C 07 2•×•• %•.-␍!'•,•
000000f0 14 0A 20 31 15 13 2C 3B 0F 12 1A 2D 0C 11 32 11 •⏎ 1••,;•••-••2•

it’s much easier to pick out the unique byte when it’s a different color! human brains are really good at spotting visual patterns—given the right format.