Binary Octal Hex Converter
Convert numbers between binary, octal, decimal and hexadecimal.
The four bases programmers use
Binary, octal, decimal and hexadecimal are the number bases that come up in computing, and moving a value between them is a constant small task when working close to the machine. This converts a number across all four at once, so you can see a decimal in binary, decode a hex value, or read an octal permission without doing the base arithmetic by hand.
Enter a number in any base and see it in the others.
How the bases relate
These four are not arbitrary. Binary is how computers actually store numbers. Hexadecimal is popular because each hex digit is exactly four binary bits, making it a compact shorthand for binary, which is why byte values, colours and memory addresses appear in hex. Octal, where each digit is three bits, survives mainly in file permissions. Decimal is just what humans count in. Seeing a number in all four at once makes these relationships concrete and turns base conversion from a chore into a glance.
Questions & answers
Which bases does it convert between?
Binary, octal, decimal and hexadecimal — the four that come up in computing — all at once.
Why is hex used as shorthand for binary?
Because each hex digit maps to exactly four binary bits, so hex writes binary values compactly and readably.
Is anything uploaded?
No. The conversion happens in your browser.