Number Base Converter

Developers move between number systems all the time: hex in memory dumps and color codes, binary in bit flags and permissions, octal in Unix file modes, and decimal everywhere else. Enter a number in any base to see it in all of them.

Decimal       255
Hexadecimal   0xFF
Binary        0b1111_1111
Octal         0o377

• Edit any base

  Type in the decimal, hex, binary, octal, or custom-base field and the others update as you type.

• No size limit

  Uses arbitrary-precision integers (BigInt), so 64-bit, 128-bit, and even larger numbers convert exactly.

• Two's complement

  See negative numbers as 8, 16, 32, 64, or 128-bit patterns, and read any bit pattern as signed or unsigned.

• Bit editor

  Click individual bits to flip them, which is handy for flags, masks, and register values.

• Forgiving input

  Accepts 0x, 0b, and 0o prefixes, # for hex, and digit separators like 1111_0000 or 1,000,000.

• Any base up to 36

  Convert to base 3, base 32, base 36, or any other base, using digits 0-9 and letters a-z.

1. Type a number into the field of its base: decimal, hex, binary, octal, or a custom base.
2. Read the result in every other base; copy any of them with a prefix.
3. Choose a bit width to see the two's complement form and signed and unsigned values.
4. Click bits in the bit editor to flip them.