Text to character codes

How it works

Computers store characters as numbers. ASCII, from 1963, numbers 128 characters: the capital A is 65, a space 32, the digit 0 is 48. Unicode extends this to more than a million code points, written U+ followed by at least four hex digits, so that every script and every emoji has its own number: é is U+00E9 (233), the euro sign U+20AC, 😀 U+1F600.

This tool shows each character’s code point in several bases. Going from decimal to binary or hex is the usual change of base: write the number as a sum of powers of 2 or of 16. Going back, it reads codes in the chosen base, or with a prefix such as U+, 0x or the HTML entity form é.

A code point is not yet a byte sequence: to store or send text it has to be encoded, most often in UTF-8, where a code point takes 1 to 4 bytes. Code points U+D800 to U+DFFF are reserved for the surrogates of UTF-16 and are never characters by themselves.