What is ASCII?

Before emoji and Unicode, there was ASCII — a simple 7-bit code from the 1960s that assigned numbers to English letters, digits and basic symbols. It's small, ancient, and still living inside UTF-8 today.

128 characters

ASCII defines 128 code points (0–127): uppercase and lowercase A–Z, digits 0–9, punctuation, space, and control characters like newline and tab. “A” is 65, “a” is 97, “0” is 48. Seven bits was enough for English, and that simplicity made it universal.

Its limits

ASCII has no accented letters, no other scripts, and certainly no emoji. Countless incompatible “extended ASCII” and regional encodings tried to bolt on more characters, causing the mess Unicode later cleaned up.

ASCII lives on

UTF-8 was designed so its first 128 values are identical to ASCII. That means every ASCII file is already valid UTF-8, and English text costs one byte per character — a big reason UTF-8 spread so smoothly.

Frequently asked questions