ASCII Code Converter

Convert between the 128 standard ASCII characters and codes 0–127 in decimal, hexadecimal, binary, and octal.
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ASCII Ranges Quick Reference

What is ASCII?

ASCII (American Standard Code for Information Interchange) is a character encoding standard created in 1963. It assigns numeric codes (0–127) to 128 characters: English letters, digits, punctuation marks, and control characters. UTF-8 preserves those 128 assignments as identical single-byte values.

Character encodings map text to numeric values and bytes. This ASCII code converter shows the standard 0–127 values in decimal (base-10), hexadecimal (base-16), binary (base-2), and octal (base-8).

For a complete reference of all 128 characters, see our full ASCII table. The ASCII, UTF-8, and Unicode guide explains what changes above code 127. To convert entire strings, use the Hex to ASCII converter or the Text to Hex converter.

Frequently Asked Questions

What is an ASCII code converter?
An ASCII code converter translates between the 128 standard ASCII characters and their numeric values. Type an ASCII character to see its decimal, hexadecimal, binary, and octal representation — or enter a code from 0 to 127 to find the corresponding character.
How do I find the ASCII code of a character?
Type or paste one standard ASCII character into the "Character" field. The tool shows its value in decimal, hex (base-16), binary (base-2), and octal (base-8). For example, "A" is decimal 65, hex 41, binary 01000001, and octal 101. Non-ASCII characters are rejected rather than mislabeled.
What is the ASCII code for the letter A?
Uppercase "A" has ASCII code 65 (decimal), 41 (hex), 01000001 (binary). Lowercase "a" is 97 (decimal), 61 (hex), 01100001 (binary). The difference between uppercase and lowercase is always 32 in decimal (or 0x20 in hex).
How many ASCII characters are there?
The standard ASCII table defines 128 codes (0–127): 33 control codes (0–31 and 127), 1 printable space (32), and 94 graphic characters (33–126) including letters, digits, and punctuation. Eight-bit extensions vary by encoding and are not part of ASCII itself.
What is the difference between ASCII and Unicode?
ASCII defines 128 characters using 7 bits — enough for basic English text. Unicode 17.0 assigns 159,801 graphic and format characters across 172 scripts. UTF-8 (the most common Unicode encoding) is backward-compatible with ASCII: codes 0–127 are identical, while characters beyond ASCII use multi-byte sequences.
How do I convert ASCII codes to characters in Python?
Use chr() to convert a code to a character: chr(65) returns "A". Use ord() for the reverse: ord("A") returns 65. For hex input: chr(0x41) also returns "A". In JavaScript: String.fromCharCode(65) returns "A", and "A".charCodeAt(0) returns 65.