Everyday tools · runs locally
Convert number bases
Binary, octal, decimal, hex — any of them to any of them, with the working shown.
- 1Type a number
In whichever base you have it — set the input base first.
- 2All bases update live
Binary, octal, decimal and hex at once, plus a custom base box, selectable two's-complement width and 4/8-bit grouping.
- 3Copy or send it back
Copy any row, or use the decimal/hex/binary button to put that result back in the input and keep going.
Questions people actually ask
Why binary for 255 is long — got a shortcut?
That's what 255 is in binary, and the box can group it into 4-bit nibbles or 8-bit bytes to make it readable. Hex exists precisely because nobody enjoys reading raw binary.
Negative numbers?
The sign is kept on the raw rows, and the two's-complement row shows the signed bit pattern for 8-, 16-, 32- or 64-bit widths. Values outside that range say so instead of silently wrapping.