ASCII and Unicode

Two standard character sets are ASCII and Unicode.


The ASCII character set is a 7-bit set of codes that allows 128 different characters. That is enough for every upper-case letter, lower-case letter, digit and punctuation mark on most keyboards. ASCII is only used for the English language.

This table shows some examples of letters represented using the ASCII character set:

CharacterDenary valueBinary valueHex

Extended ASCII

Extended ASCII code is an 8-bit character set that represents 256 different characters, making it possible to use characters such as é or ©. Extended ASCII is useful for European languages.


Unicode uses between 8 and 32 bits per character, so it can represent characters from languages from all around the world. It is commonly used across the internet. As it is larger than ASCII, it might take up more storage space when saving documents.

Global companies, like Facebook and Google, would not use the ASCII character set because their users communicate in many different languages.

Pie chart showing that ASCII has 128 characters and Unicode has over 1.1 million
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