0x69 · 1101001

ASCII 105 — the i character

Lowercase

i is 105 in decimal, 69 in hex and 1101001 in binary. It sits 32 away from I.

a starts at 97 — the capital plus 32.

Seven bits

ASCII is seven bits wide, which is why there are 128 of them. The eighth bit was long left for parity.

1101001

One bit — the sixth, worth 32 — separates the cases. Off gives a capital, on gives a lowercase letter.

Kind: Lowercase
Decimal: 105
Hexadecimal: 0x69
Octal: 151
Binary: 1101001
HTML entity: i
URL encoding: i
CSS escape: \69
With Ctrl held: HT (9)
Case pair: I (73)

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.

Codes either side

102 · f 103 · g 104 · h 106 · j 107 · k 108 · l

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 i?

Decimal 105, hex 69, octal 151, binary 1101001.

Q. How do I write i in HTML?

As i.

Q. How does it go in a URL?

It can stay as it is — this character needs no encoding.

Q. Does i have a partner?

I — the codes are 32 apart.