91
[
0x5B · 1011011
ASCII 91 — the [ character
Punctuation
[ is 91 in decimal, 5B in hex and 1011011 in binary.
The marks scattered between the digits and the letters.
Seven bits
ASCII is seven bits wide, which is why there are 128 of them. The eighth bit was long left for parity.
1011011
One bit — the sixth, worth 32 — separates the cases. Off gives a capital, on gives a lowercase letter.
- Kind
- Punctuation
- Decimal
- 91
- Hexadecimal
- 0x5B
- Octal
- 133
- Binary
- 1011011
- HTML entity
- [
- URL encoding
- %5B
- CSS escape
- \5B
The chart
Eight columns for the top three bits, sixteen rows for the bottom four. The capitals column sits right beside the lowercase one — that is the shape of the table.
0NUL1SOH2STX3ETX4EOT5ENQ6ACK7BEL8BS9HT10LF11VT12FF13CR14SO15SI16DLE17DC118DC219DC320DC421NAK22SYN23ETB24CAN25EM26SUB27ESC28FS29GS30RS31US32SP33!34"35#36$37%38&39'40(41)42*43+44,45-46.47/48049150251352453554655756857958:59;60<61=62>63?64@65A66B67C68D69E70F71G72H73I74J75K76L77M78N79O80P81Q82R83S84T85U86V87W88X89Y90Z91[92\93]94^95_96`97a98b99c100d101e102f103g104h105i106j107k108l109m110n111o112p113q114r115s116t117u118v119w120x121y122z123{124|125}126~127DEL
Codes either side
How to read this
- Add 32 to a capital and you get the lowercase letter — one bit flips.
- Digits start at 48, so subtracting 48 from the code gives the number.
- Holding Ctrl clears the top three bits — that is why Ctrl+I is a tab.
- Everything under 32, plus 127, draws nothing. Those show their abbreviation instead.
Frequently asked questions
Q. What is the ASCII code for [?
Decimal 91, hex 5B, octal 133, binary 1011011.
Q. How do I write [ in HTML?
As [.
Q. How does it go in a URL?
It is encoded as %5B.
Q. Does [ have a partner?
No case partner: it is not a letter but a symbol.