ASCII 101
Latin Small Letter E (e)
Printable ASCII
Lowercase letter e. ASCII code 101. The most frequent letter in English text, which is why it anchors frequency-analysis attacks on simple substitution ciphers. Also the base of natural logarithms and the exponent marker in float literals.
Common uses & context
Thelowercase letter 'e' has ASCII code 101 (0x65). Its uppercase twin 'E' sits exactly 32 code points away at 69. That constant gap of 32 — a single bit, 0x20 — is why changing letter case is one of the cheapest operations a CPU can do: you flip or mask one bit rather than looking anything up. Lowercase letter e. ASCII code 101. The most frequent letter in English text, which is why it anchors frequency-analysis attacks on simple substitution ciphers. Also the base of natural logarithms and the exponent marker in float literals.
The lowercase Latin letters form the contiguous block 97–122, so range checks like c >= 'a' && c <= 'z' work without a lookup table. To convert 'e' to its uppercase form youclear bit 5: 'e' & ~0x20 gives 'E'. Because uppercase (65–90) sorts before lowercase (97–122) in raw byte order, naive sorting places every capitalized wordahead of every lowercase one — the reason "Zebra" comes before "apple" unless you sort case-insensitively.
'e' is also a hexadecimal digit: in base-16 it represents the value 14. Hex uses 0–9 for 0–15's firstten values and A–F (or a–f) for 10–15, so 'e' is valid inside literals like 0xee and colour codes like #eeeeee.
All encodings at a glance
| Decimal | 101 |
| Hexadecimal | 0x65 |
| Octal | 0145 |
| Binary | 01100101 |
| HTML numeric entity | e |
| URL encoding | %65 |
| UTF-8 bytes | 0x65 |
Code snippets
JavaScript
String.fromCharCode(101); // "e"
101.toString(16); // "65"Python
chr(101) # 'e'
ord(chr(101)) # 101
hex(101) # '0x65'HTML
e <!-- numeric entity (no named entity for this character) -->Programming notes
- ▸Case toggle: 'e' & ~0x20 = 'E' (a single-bit change).
- ▸Letter test: c >= 'a' && c <= 'z' — the lowercase block is contiguous (97–122).
- ▸As a hex digit, 'e' has value 14 in base-16.
Frequently asked questions
What character is ASCII code 101?
ASCII code 101 is the character 'e' (Latin Small Letter E). In hexadecimal it is 0x65, in octal 0145, and in binary 01100101.
What is 0x65 in ASCII?
Hexadecimal 0x65 equals decimal 101, which is the character 'e' (Latin Small Letter E). To convert hex to ASCII yourself, read the two hex digits as a base-16 number (0x65 = 101) and look up that code point.
How do I write the character with code 101 in code?
In JavaScript use String.fromCharCode(101); in Python use chr(101); in HTML use the numeric entity e. In a URL it is percent-encoded as %65, and in UTF-8 it is stored as the byte sequence 0x65.
What is the uppercase form of 'e' in ASCII?
'e' is code 101; its uppercase counterpart 'E' is code 69. The two always differ by 32, so you can convert by subtracting 32 (or clearing bit 0x20).