Number Base Converter
Convert between Binary, Octal, Decimal and Hexadecimal โ type in any field.
About Number Bases
A number base (or radix) defines how many unique digits are used to represent numbers. Decimal (base 10) uses digits 0โ9 and is the everyday system. Binary (base 2) uses only 0 and 1 and is how computers store and process data at the hardware level. Octal (base 8) uses digits 0โ7 and appears in Unix file permissions (e.g. chmod 755). Hexadecimal (base 16) uses 0โ9 and AโF; it's widely used in programming for colour codes, memory addresses and byte values because one hex digit represents exactly 4 bits.
Type in any field and all others update instantly. The bit display under the binary field groups bits in sets of 4 for easy reading. The custom base field supports any base from 2 to 36 (using letters for digits above 9).
How to Use
- Type a number into any of the four base fields โ all others update instantly.
- The bit display shows the binary representation grouped in nibbles (4 bits).
- Use the Custom base row to convert to any base from 2 to 36.
- Click any field to select all text for easy copying.
Frequently Asked Questions
11111111 = hex FF). It's much more compact than binary and easier to convert to binary than decimal. Programmers use it for memory addresses, colour codes (#FF5733), byte values, and bitmasks.BigInt for all conversions, which supports arbitrarily large integers with no size limit. You can convert numbers with hundreds of digits. The binary bit display is capped at 128 bits for readability; larger numbers show the full value without grouping.