Number Base Converter (Dec/Hex/Bin/Oct)
Type a number in any base and see it in decimal, hex, binary, and octal instantly. Negatives are shown as two's complement at your chosen bit width. Everything runs in your browser — nothing is uploaded.
| Decimal | — | |
|---|---|---|
| Hex | — | |
| Binary | — | |
| Octal | — |
| Unicode | — | Decimal | — |
|---|---|---|---|
| Hex | — | Octal | — |
| Binary | — | ||
About this tool
Converts between decimal, hexadecimal, binary, and octal using JavaScript's BigInt, so values of any size — including full 64-bit integers — convert without floating-point rounding. Prefixed input (0x, 0b, 0o) is auto-detected, underscores and spaces are ignored as digit separators, and negative numbers are additionally shown as their two's complement bit pattern at the selected width, the same representation your CPU and most languages use for signed integers.
Your data never leaves the page — there is no server, no upload, and no tracking of tool inputs.