Number Base Converter
Convert numbers between decimal, binary, hexadecimal, and octal. Edit any field to update the rest live.
Base 10 — digits 0–9
Base 2 — digits 0–1
Base 16 — digits 0–9, A–F
Base 8 — digits 0–7
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How to Convert Decimal, Binary, Hex, and Octal
This number base converter translates unsigned integers between decimal, binary, hexadecimal, and octal as you type. It uses BigInt, so values larger than JavaScript’s Number.MAX_SAFE_INTEGER (2^53 − 1) keep their precision.
Invalid digits for the active base are flagged instead of silently rounding. Pair it with the color converter when you are working with hex colors rather than integer hex.
Tips
- Binary uses 0 and 1 only; octal 0–7; hex 0–9 and A–F.
- Copy the prefixed form (
0x,0b,0o) when pasting into source code. - Negative numbers and fractions are not converted — this tool is for unsigned integers.