Introduction
ASCII (American Standard Code for Information Interchange) assigns numeric codes to characters, symbols, and control bytes. Programmers convert text to ASCII decimal, hex, or binary when working with serial protocols, file formats, encoding exercises, and low-level string manipulation.
The Numverto ASCII Converter encodes any text string into code points and decodes numeric input back to characters. See our complete ASCII table and ASCII complete reference for details.
ASCII Encoding Method
Standard ASCII uses 7 bits (0–127). Extended ASCII reaches 255. Each character maps to a fixed code: A=65, a=97, 0=48, space=32. Hex and binary are positional representations of the same code value.
Step-by-Step Examples
Example: Letter "A"
Decimal 65, Hex 41, Binary 01000001.
Example: String "Hi"
H = 72 (0x48), i = 105 (0x69). Concatenated hex often written as 4869 for raw bytes.
Real-Life Applications
- Serial communication and UART debugging
- CTF challenges and encoding puzzles
- Learning character encoding fundamentals before Unicode
- Hex dumping and reverse engineering text sections
- Computer science lab exercises on data representation
Advantages of Using This ASCII Converter
- Bidirectional text ↔ code conversion
- Multiple output formats: decimal, hex, binary, octal
- Handles multi-character strings in one pass
- Copy individual code values quickly
- Works on mobile for field debugging
Common Mistakes to Avoid
- Confusing ASCII codes with Unicode code points
- Off-by-one errors between uppercase and lowercase (difference is 32)
- Forgetting that digits 0–9 start at code 48, not 0
- Using extended ASCII codes without specifying the code page
- Mixing hex string representation with actual character bytes
Learn More
- Full ASCII Reference Table
- Number System Converter
- Binary to Hex Converter
- ASCII Complete Reference
- Computer Number Systems
What is ASCII?
ASCII (American Standard Code for Information Interchange) is a character encoding standard that assigns numeric codes to 128 characters, including English letters, digits, punctuation, and control characters. Developed in the 1960s, ASCII remains the foundation of text encoding in computing.
ASCII Character Ranges
- 0–31: Control characters (newline, tab, etc.)
- 32–47: Space and punctuation
- 48–57: Digits 0–9
- 65–90: Uppercase A–Z
- 97–122: Lowercase a–z
Converting Text to ASCII Binary
Each character maps to a decimal code, which can be expressed in binary, hexadecimal, or octal. For "Hi": H=72=01001000, i=105=01101001.
Common ASCII Codes
Space=32, '0'=48, 'A'=65, 'a'=97. Knowing these offsets helps quick mental conversion: 'B' = 66, 'b' = 98.
ASCII in Programming
Functions like Python's ord() and chr(), JavaScript's charCodeAt(), and C's integer casting all rely on ASCII values. Network protocols and file formats use ASCII for headers and metadata.
Extended ASCII and Unicode
Extended ASCII (128–255) adds accented characters. Unicode (UTF-8) extends this to all world scripts while remaining ASCII-compatible for English text.