Text to ASCII Codes

ASCII, the American Standard Code for Information Interchange, was published in 1963 and formalised the relationship between human-readable characters and the binary numbers computers use internally. The standard defines 128 characters (codes 0–127): 33 non-printing control characters (codes 0–31 and 127) and 95 printable characters including uppercase and lowercase Latin letters, digits, punctuation, and the space character. Every modern encoding system, including UTF-8, UTF-16, Latin-1, and Windows-1252, is a superset of or directly compatible with ASCII for the first 128 code points.

Understanding ASCII codes is foundational to programming. String manipulation in virtually every language ultimately works on arrays of code points. Knowing that uppercase 'A' is 65 and lowercase 'a' is 97 (a difference of exactly 32) explains why toggling the sixth bit flips a letter's case. Knowing that '0' is 48 means you can convert a digit character to its integer value by subtracting 48. These patterns repeat throughout systems programming, protocol design, and file format parsing.

Hexadecimal representation (base 16) is ubiquitous in computing because each hexadecimal digit maps precisely to four binary bits (a nibble). ASCII codes expressed in hex are compact and align naturally with byte-level representations: 0x41 for 'A', 0x61 for 'a', 0x20 for space. Hex escapes appear in HTML (`A`), URLs (`%41`), CSS (`\0041`), and source code string literals (`\x41`).

Binary representation makes the bit patterns explicit. This is useful when studying character encoding, designing low-level parsers, or understanding bitwise operations on character data. Octal representation was historically common in C string literals (`\101` for 'A') and still appears in Unix file permissions and some legacy protocols.

This tool converts in both directions: type text to see every character's code, or paste a list of ASCII codes to decode them back into text. The character map table gives you all four representations simultaneously for every character in your input, making it a compact reference for encoding work, CTF challenges, protocol debugging, or learning.