ASCII Table

ASCII Reference Table

ASCII, the American Standard Code for Information Interchange, is a character encoding standard based on the Latin alphabet. It is equivalent to the international standard ISO/IEC 646.

ASCII defines 128 characters in total. Among them, codes 0–31 and 127 (33 characters) are control characters, while the remaining 95 are printable characters — including letters, digits, punctuation marks, and the space character.

See ASCII on Wikipedia for the full specification, and C0 control codes for control character details.

How to Use

Browse the ASCII Table

The page displays all 128 ASCII characters in a table. Each entry shows the character symbol, its hexadecimal value, and its decimal value for quick reference.

Characters are color-coded into three categories:

• Red — Control characters (0–31 and 127), such as NUL, TAB, LF
• Orange — Letters and digits (0–9, A–Z, a–z)
• Blue — Other printable characters, including space and punctuation

View Character Details

Click any character in the table to open its detail page, which shows the full breakdown: decimal, hexadecimal, octal, binary values, and a description.

You can also navigate directly by entering a path like /ascii/65 in the browser address bar to jump to a specific character (65 = uppercase A).

Common Use Cases

Looking up character codes while programming — For example, to find the ASCII code for a space character, locate it in the table: decimal 32, hex 0x20.

Identifying control characters — When debugging invisible characters in strings, check the red section. For instance, Line Feed (LF) is decimal 10 and Carriage Return (CR) is 13.

Quick base conversion — Click a character to see its decimal, hexadecimal, and octal representations without manual calculation.

FAQ

Q: What is the relationship between ASCII and Unicode?

ASCII was the earliest character encoding standard, covering only 128 characters — primarily English letters, digits, and common symbols. Unicode is a superset of ASCII: its first 128 code points are identical to ASCII, ensuring full backward compatibility. Unicode extends far beyond ASCII with over 140,000 characters, covering virtually every writing system in the world. In practice, UTF-8 — the most common Unicode encoding — represents ASCII characters with a single byte, just like the original standard.

Q: Why does ASCII only have 128 characters?

ASCII uses 7 bits for encoding, allowing a maximum of 2⁷ = 128 distinct characters (codes 0–127). When ASCII was designed in the 1960s, computer memory was scarce, and 7 bits were sufficient for English letters, digits, punctuation, and essential control characters. Although a byte has 8 bits, the highest bit was typically reserved as a parity bit for error detection during data transmission.

Q: What are control characters used for?

The first 32 ASCII characters (0–31) and character 127 (DEL) are control characters, originally designed to control hardware devices like teletypewriters. Several remain widely used in modern programming: LF (Line Feed, code 10), CR (Carriage Return, code 13), TAB (Horizontal Tab, code 9), and NUL (Null, code 0). Notably, the different line-ending conventions — LF on Unix/macOS versus CRLF on Windows — trace directly back to these two control characters.