ASCII Table

About ASCII Table Reference

An ASCII table (American Standard Code for Information Interchange) is a character encoding standard that assigns numeric codes to letters, digits, punctuation marks, and control characters. Our free online ASCII code reference chart provides a complete view of all 128 standard ASCII characters (0–127) plus extended ASCII (128–255) for developers, programmers, students, and IT professionals who need quick access to ASCII values in decimal, hexadecimal, binary, and HTML entity formats.

Every character you type on a keyboard corresponds to a unique ASCII code. For example, the uppercase letter "A" has ASCII code 65 (decimal), 0x41 (hex), and 01000001 (binary). Understanding ASCII codes is fundamental to computer programming, data communication, text processing, and web development. Whether you're debugging network protocols, encoding data, writing low-level software, or building web applications, having an ASCII reference chart at your fingertips saves time and reduces errors.

This tool goes beyond a simple ASCII chart. It includes a character info tool that reveals decimal, hex, binary, octal, HTML entity, URL encoding, and Unicode codepoint for any character. The binary/hex translator converts entire strings into their ASCII components. A keyboard shortcut reference lists the most frequently used ASCII codes in programming — Tab (09), Line Feed (0A), Carriage Return (0D), Space (20), and Delete (7F). All data is generated client-side using vanilla JavaScript, so no server requests are needed.

The ASCII table is organized with six columns: Decimal (0–127), Hexadecimal (00–7F), Binary (00000000–01111111), the Character glyph (for printable characters) or its control name (for non-printable codes 0–31 and 127), the HTML entity code (e.g., & for ampersand, < for less-than), and a brief description. Non-printable control characters are displayed with their official abbreviations such as NUL, SOH, STX, ETX, EOT, ENQ, ACK, BEL, BS, TAB, LF, VT, FF, CR, SO, SI, DLE, DC1, DC2, DC3, DC4, NAK, SYN, ETB, CAN, EM, SUB, ESC, FS, GS, RS, US, and DEL.

Extended ASCII (128–255) covers the Latin-1 Supplement block used in many Western European languages, including accented letters (é, ü, ñ), mathematical symbols (×, ÷, ±), currency symbols (¢, £, ¥), and typographic marks (©, ®, ™). Toggle the extended ASCII switch to expand the table from 128 to 256 entries. Categories help you filter by control characters, digits, uppercase letters, lowercase letters, punctuation, and extended codes.

The interface features a responsive card layout that adapts to mobile screens — on small devices, the table transforms into a two-column card view with labeled data cells. The search bar provides real-time filtering across all columns with visual highlighting of matched rows. Category filter buttons let you quickly isolate specific character groups. Clicking any row copies the character to your clipboard. The dark/light mode toggle at the bottom-right corner lets you switch between a light glassmorphism theme and a dark slate theme for comfortable viewing in any environment.

Whether you're a seasoned developer referencing ASCII values for a project, a computer science student learning about character encoding, a cybersecurity professional analyzing data packets, or a web developer writing HTML entities, this ASCII code chart provides instant access to every value you need. Bookmark this page for quick reference whenever you need to look up ASCII codes, convert characters between formats, or understand the binary representation of text.

How to Use the ASCII Table

1. Browse the ASCII table: The main table displays all 128 standard ASCII characters sorted by decimal value. Each row shows the decimal code, hexadecimal code, binary representation, the character glyph (or control name for non-printable codes), HTML entity, and a short description.
2. Search for specific codes: Type a character, decimal number, hex value (with or without 0x prefix), or keyword in the search bar. The table filters in real-time, and matching rows are highlighted with a yellow background for quick identification.
3. Filter by category: Use the category buttons above the table to show only specific groups: Control Characters (0–31), Punctuation & Symbols, Digits (48–57), Uppercase Letters A–Z (65–90), Lowercase Letters a–z (97–122), or Extended ASCII (128–255).
4. Toggle extended ASCII: Enable the "Show Extended ASCII" switch to append codes 128–255 to the table. These include Latin-1 Supplement characters such as accented letters, currency symbols, and typographic marks used in Western European languages.
5. Copy a character: Click any row in the ASCII table to instantly copy the character to your clipboard. A toast notification confirms the copy action. This is useful when you need to insert a specific character into your code or document.
6. Use the Character Info tool: Switch to the "Char Info" tab and type any single character to see its complete encoding details: decimal, hex, binary, octal, HTML entity, URL-encoded form (%XX), Unicode codepoint (U+XXXX), and Unicode category (letter, digit, punctuation, control, symbol, etc.).
7. Translate text with Binary/Hex Translator: Switch to the "Translator" tab and enter any text string. The tool breaks it down character by character, showing each one's decimal, hex, and binary values in a sortable table. Use the Copy buttons to copy individual values or entire columns at once.
8. Reference keyboard shortcuts: The "Shortcuts" tab lists the most commonly used ASCII codes in programming and data processing — Tab (09), Line Feed/LF (0A), Carriage Return/CR (0D), Space (20), and Delete (7F). Each card shows the decimal, hex, binary, and escape sequence for quick reference.

Frequently Asked Questions

The History and Significance of ASCII

The Birth of a Standard

The American Standard Code for Information Interchange (ASCII) was developed in the early 1960s by a committee of the American Standards Association (ASA), now ANSI. The primary goal was to create a universal character encoding standard that would allow different computer systems and telecommunication equipment to exchange data reliably. Before ASCII, each manufacturer used proprietary encoding schemes — IBM had EBCDIC, telegraph systems used Baudot code, and various teletype machines had their own 5-bit and 6-bit codes. This fragmentation made data exchange between systems extremely difficult and error-prone.

Design and Architecture

ASCII was designed as a 7-bit encoding scheme, providing 128 unique code points (2^7 = 128). The decision to use 7 bits was practical at the time — most data transmission used 8-bit bytes (octets), leaving the eighth bit available for parity checking (error detection). The 128 codes were organized into logical groups: codes 0–31 were reserved for control characters that managed data flow and device behavior; code 32 was the space character; codes 33–47 covered punctuation and symbols; codes 48–57 represented the digits 0–9; codes 58–64 held more punctuation; codes 65–90 were uppercase letters A–Z; codes 91–96 had additional punctuation and brackets; codes 97–122 were lowercase letters a–z; codes 123–126 contained the remaining punctuation; and code 127 was the DEL control character. This thoughtful organization made ASCII both logical and easy to work with — for example, converting between uppercase and lowercase requires only toggling a single bit (bit 5).

The Control Characters

ASCII's control characters (0–31, 127) reflect its heritage in teletype and serial communication. NUL (0) was used as a filler or for time-filling. SOH (1) through ETX (3) framed message headers. BEL (7) triggered a bell on the terminal. BS (8) moved the cursor back one position. TAB (9) advanced to the next tab stop. LF (10) moved the paper up one line (line feed). CR (13) returned the carriage to the left margin. ESC (27) introduced escape sequences for extended commands. These control codes were essential for operating teleprinters, paper tape readers, and early video terminals. Many of these codes survive in modern computing — LF and CR remain the standard line terminators in Unix/Linux and Windows respectively; TAB is universal for indentation; ESC is used in terminal escape sequences and keyboard shortcuts.

From 7-Bit ASCII to 8-Bit Extensions

As computing evolved, the limitation of 128 characters became apparent. The eighth bit, originally used for parity, was repurposed to double the character set to 256 codes (0–255). This led to the development of multiple "extended ASCII" code pages. The IBM PC popularized Code Page 437 (CP437), which added line-drawing characters, mathematical symbols, and Greek letters. The ISO 8859 standard series defined 15 different 8-bit encodings for various language families — ISO 8859-1 (Latin-1) covered Western European languages with accented characters like é, ü, ñ, and symbols like ©, ®, £, ¥. Windows-1252, Microsoft's superset of Latin-1, became widely used on Windows systems.

Unicode and UTF-8: ASCII's Legacy

Today, Unicode has superseded ASCII as the universal character encoding standard, capable of representing over 140,000 characters from every major writing system. However, ASCII's influence is deeply embedded in Unicode's design. The first 128 Unicode code points (U+0000 to U+007F) are identical to ASCII, ensuring perfect backward compatibility. Furthermore, UTF-8 — the dominant encoding on the World Wide Web — encodes ASCII characters as single bytes with the highest bit set to 0, while multi-byte sequences use bytes with the highest bit set to 1. This means every valid ASCII text is also valid UTF-8. When Tim Berners-Lee chose UTF-8 for the World Wide Web, ASCII's legacy was cemented for the internet age.

Why ASCII Still Matters

Despite being over six decades old, ASCII remains relevant in modern computing. It is the foundation of most programming language syntax — all keywords, operators, and punctuation in C, Java, JavaScript, Python, and virtually every mainstream language are ASCII. Network protocols (HTTP, SMTP, FTP) use ASCII for their headers and commands. File formats like JSON, XML, and CSV are ASCII-compatible. Low-level debugging, binary data analysis, embedded systems programming, and cybersecurity work all require a solid understanding of ASCII codes. The simplicity and universality of ASCII make it an enduring standard that every programmer, developer, and IT professional should understand thoroughly.

Conclusion

ASCII is far more than a historical curiosity — it is the bedrock of digital text representation. From the bytes that form this very webpage to the protocols that delivered it to your browser, ASCII's fingerprints are everywhere. Whether you're a student learning about character encoding, a developer debugging network traffic, a security researcher analyzing data, or a programmer writing your first "Hello World" program, understanding the ASCII table is an essential skill. Bookmark our ASCII table reference chart for quick access to every code, from NUL (0) through DEL (127), plus extended ASCII codes for Latin-1 characters (128–255).