Free Online ASCII Converter
Convert any text to ASCII codes or ASCII values back to readable text instantly. Our tool supports decimal, hexadecimal, binary, and octal representations. Everything runs in your browser — your data never leaves your device.
What is ASCII?
ASCII (American Standard Code for Information Interchange) is a character encoding standard that assigns numeric values to letters, digits, punctuation marks, and control characters. Developed in the early 1960s and published as a standard in 1963, ASCII was one of the first widely adopted character encoding systems in computing.
The standard ASCII table defines 128 characters: 33 non-printing control characters (0–31 and 127) and 95 printable characters (32–126) including uppercase and lowercase letters, digits 0 through 9, punctuation, and the space character. Each character is represented by a 7-bit binary number, allowing values from 0 to 127.
History of ASCII
ASCII was developed by a committee of the American Standards Association (now ANSI) beginning in 1960. The first edition was published in 1963, with major revisions in 1967 and 1986. Before ASCII, different computer manufacturers used incompatible character encoding schemes like EBCDIC (used by IBM mainframes), making data exchange between systems difficult.
ASCII became the dominant encoding for the early internet and remains the foundation of modern character encoding systems. Its 7-bit design reflected the hardware constraints of 1960s telecommunications, where the eighth bit was often reserved for error checking (parity bit).
Character Encoding Explained
Character encoding is the process of mapping characters (letters, symbols, control codes) to numeric values that computers can store and process. When you type the letter “A” on your keyboard, the computer stores the number 65 (its ASCII code). When displaying text, the computer reverses this mapping to render the correct glyph.
In JavaScript, you can use charCodeAt() to get the numeric code of a character and String.fromCharCode() to convert a numeric code back to a character. These are the same functions this tool uses under the hood.
ASCII vs Unicode
| Feature | ASCII | Unicode |
|---|---|---|
| Characters | 128 (7-bit) | 149,813+ (up to 21-bit) |
| Languages | English only | All modern & historic scripts |
| Encoding size | 7 bits per character | 8–32 bits (varies by encoding) |
| Common encodings | US-ASCII | UTF-8, UTF-16, UTF-32 |
| Compatibility | Subset of Unicode | Superset of ASCII |
| Emoji support | No | Yes |
The first 128 Unicode code points are identical to ASCII, meaning every valid ASCII text is also valid UTF-8. Unicode extends far beyond ASCII to support characters from virtually every writing system in the world, as well as emoji, mathematical symbols, and historical scripts.
Frequently Asked Questions
An ASCII code is a numeric value assigned to a character by the ASCII standard. For example, the letter 'A' has ASCII code 65 (decimal), 41 (hex), or 01000001 (binary). ASCII defines 128 characters total, including letters, digits, punctuation, and control characters.
Enter your text in the input field with 'Text → ASCII' mode selected. Each character is converted to its numeric ASCII code using the charCodeAt() function. Choose your preferred format (decimal, hex, binary, or octal) to see the values in that number system.
ASCII uses 7 bits to represent 128 characters (English only). UTF-8 is a variable-length encoding that uses 1–4 bytes per character and can represent over 149,000 characters from all languages. The first 128 UTF-8 characters are identical to ASCII, making ASCII a subset of UTF-8.
Control characters (codes 0–31 and 127) are non-printing characters used for text formatting and device control. Examples include Null (0), Tab (9), Line Feed (10), Carriage Return (13), and Escape (27). They were originally used to control teletypes and terminals.
Yes. All conversions happen entirely in your browser using JavaScript's built-in charCodeAt() and String.fromCharCode() functions. No data is sent to any server — everything runs 100% client-side.
This tool uses JavaScript's charCodeAt(), which returns the UTF-16 code unit. For standard ASCII characters (0–127), the values are identical. Characters outside the ASCII range (like accented letters or emoji) will return their Unicode code point, which extends beyond the 0–127 ASCII range.
ASCII uses 7 bits to encode characters, which allows for 2⁷ = 128 unique values (0–127). This was a practical choice for 1960s hardware. The 8th bit was often used as a parity bit for error detection during serial data transmission.
The space character has ASCII value 32 (decimal), 20 (hex), or 00100000 (binary). It is the first printable character in the ASCII table, though it renders as a blank space. Characters 0–31 are non-printing control characters.