Binary, hex, decimal and octal converter

How the input base is detected

With "Detect", 0x means hexadecimal, 0b binary and 0o octal. A number made only of digits 0-9 is read as decimal, and one containing the letters a-f (such as ff) as hexadecimal. If a value like 1010 is meant as binary, choose "Binary" as the input base instead of relying on detection.

Exact for any size

The conversion uses arbitrary-precision integers, so 64-bit values such as 18446744073709551615 (0xFFFFFFFFFFFFFFFF) stay exact, unlike many calculators that round above 2^53. Underscores and spaces inside a number are ignored, so 1111_0000 and FF FF are accepted.

Negative numbers

A minus sign is kept in front of every result, for example -42 is -0x2A. This is the signed value, not the two's complement bit pattern a CPU would store; for a 32-bit two's complement of a negative number, add 2^32 (4294967296) first.

Example

Three numbers written in different bases, detected from their prefix.

Input

255
0xFF
0b1010

Output

255  ->  dec 255 | hex 0xFF | oct 0o377 | bin 1111 1111
0xFF  ->  dec 255 | hex 0xFF | oct 0o377 | bin 1111 1111
0b1010  ->  dec 10 | hex 0xA | oct 0o12 | bin 1010

How to use

1. Type or paste your text in the box above.
2. The result updates as you type; change the options to switch mode.
3. Copy the result or download it.

FAQ

How do I convert hex to decimal?

Type the hex value with or without 0x, for example 0xFF or ff. The decimal value (255) is shown first on the result line.

Why is binary shown in groups of four?

Each group of four bits is exactly one hexadecimal digit, which makes binary easier to read and to compare with the hex value.

Does it handle fractions?

No, only whole numbers (integers).

Is anything uploaded?

No. Everything is computed in your browser.