SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/tech-hex-digit-four-bits

How many bits does one hexadecimal digit (0 to F) stand for?

4 bits, so one byte is exactly two hex digits.

Start playing free

  1. 2 bits
  2. 8 bits
  3. 4 bits ✔

Why: Hex has 16 symbols, and 4 bits make exactly 16 patterns. So every byte (8 bits) is written as two hex characters, like FF for 255. That neat fit is why programmers love hex.

Huh, didn't know that: The hex alphabet is 0 to 9 then A to F, and RFC 4648 says hex is case insensitive, so ff and FF are the same.

The dad joke
Why do programmers like hex? Because it is the base of all their jokes.
Like this card?
Play the game

References

Answer: 4 bits. Hex has 16 symbols, and 4 bits make exactly 16 patterns. So every byte (8 bits) is written as two hex characters, like FF for 255. That neat fit is why programmers love hex.

  1. RFC 4648: The Base16, Base32, and Base64 Data Encodings www.rfc-editor.org/rfc/rfc4648.txt
    These 8 bits are then treated as 2 concatenated 4-bit groups, each of which is translated into a single character
    Checked 2026-10-10.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

Tech & GadgetsHow many different values can 8 bits represent?Tech & GadgetsHow do nearly all computers store negative whole numbers in binary?Tech & GadgetsWhat is the range of an 8-bit signed (two's complement) integer?

That's stuff everyone should know.