ASCII / Unicode Converter
Convert between text and ASCII/Unicode codes with encoding tools
Text to Code
About this tool
The ASCII converter is a free tool that converts between text and ASCII codes in decimal, hexadecimal, and binary. You can inspect the code value of each character and the matching control characters, which helps with learning programming, debugging, and understanding character encodings. It is handy for checking mappings like "A is 65" and "a is 97", or for working out how characters are represented in escaping and data transmission.
How to use
- 1 Choose the direction: text to code, or code to text.
- 2 Enter the string or list of codes you want to convert.
- 3 Codes appear in your chosen notation: decimal, hex, or binary.
- 4 Use the ASCII table to look up the mapping between characters and numbers.
How it works
ASCII (American Standard Code for Information Interchange) is a 7-bit character standard from 1963. Seven bits represent 128 values from 0 to 127: codes 0-31 and 127 are control characters such as newline and tab, while 32-126 are printable characters like letters, digits, and symbols. Capital A is 65 and lowercase a is 97; the gap of 32 is used for case conversion. The digit 0 starts at 48. Modern UTF-8 is fully compatible with ASCII: codes 0-127 are stored in a single byte exactly as in ASCII, while characters such as Japanese use more bytes. As a result, data containing only letters and digits is treated identically as ASCII or UTF-8.
Frequently asked questions
How do ASCII, Unicode, and UTF-8 differ?
ASCII is an old 128-character standard, Unicode covers virtually every language, and UTF-8 is a Unicode encoding whose first 128 characters are fully ASCII-compatible.
Why are uppercase and lowercase codes offset?
In ASCII, capital A (65) and lowercase a (97) are always 32 apart. This regular gap lets you switch case with a simple bit operation.
What are control characters?
They are the non-printing characters assigned to 0-31 and 127, such as newline (10), carriage return (13), and tab (9), which control text structure.
Can ASCII represent Japanese?
No. ASCII only covers letters, digits, and symbols. Japanese is represented with encodings like UTF-8 or Shift_JIS that use more bytes per character.
Related tools and uses
To explore code values in hex and binary, the number base converter is useful. When matching characters with patterns, see the regex tester, and for hex color values try the color code converter.