ASCII and Unicode Code Points Explained
Every character stored in a computer has a numeric identifier. ASCII and Unicode are the two most widely used standards that define those numbers. This tool lets you look up code values for any character, or find the character for any code point — in both directions, instantly.
ASCII Basics
ASCII (American Standard Code for Information Interchange) was established in 1963 as a 7-bit encoding standard, defining 128 characters numbered 0–127. Uppercase 'A' is 65, lowercase 'a' is 97 (difference of 32), and the space character is 32. Characters 0–31 and 127 are non-printable control characters such as newline (10), tab (9), and null (0). Extended ASCII (128–255) varies by region and is less standardized.
Unicode and Code Points
Unicode is the international standard for encoding all the world's writing systems in a single unified scheme. Code points range from U+0000 to U+10FFFF, providing over 1.1 million slots — about 150,000 are currently assigned. ASCII characters map directly to U+0000–U+007F, making Unicode fully backward-compatible. Emojis live primarily in the U+1F300 and higher ranges.
Practical Uses
In HTML, special characters can be written as numeric entities (A for A). In CSS, Unicode escapes use a backslash (\0041). In Python, use ord('A') for the code and chr(65) for the character. In JavaScript, 'A'.codePointAt(0) and String.fromCodePoint(65) are the equivalents. Knowing code points is also useful when working with regular expressions, data sanitization, and font rendering issues.
Frequently Asked Questions
- What is the difference between UTF-8 and Unicode?
- Unicode assigns numbers to characters. UTF-8 is one of several ways to encode those numbers as bytes. UTF-8 is backward-compatible with ASCII and uses 1 byte for ASCII characters and up to 4 bytes for others.
- Why do some emojis show multiple code points?
- Some emojis are composed of multiple Unicode characters joined by a Zero Width Joiner (ZWJ, U+200D). For example, a family emoji can be a sequence of person, ZWJ, and other person characters.