Number base — bin / oct / dec / hex
Convert between binary, octal, decimal, and hexadecimal in one step. Toggle the input base (Mode) and the other three are computed instantly. Optional 0b / 0o / 0x prefixes and 4-digit grouping. Powered by BigInt for full precision, all inside your browser.
How to use
Pick an input base (Mode: BIN / OCT / DEC / HEX) and type the value. The other three bases update live. Each card has its own Copy button. Toggle Add prefixes to prepend 0b / 0o / 0x and Group every 4 digits to insert spaces every four digits from the right (e.g., binary 1010 1011). Values are computed with BigInt so there is effectively no upper digit limit.
FAQ
- Is my value uploaded?
- No. BigInt conversion runs entirely in your browser, so even sensitive register dumps or memory addresses stay local.
- How large can the input be?
- We use BigInt, so the theoretical limit is your browser's memory. Practically the tool handles thousands of digits without issue, well beyond JavaScript Number precision (2^53).
- Are negative numbers supported?
- Toggle Allow negative sign to accept a leading minus. We treat values as signed integers (not two's complement), so -171 dec maps directly to -ab hex.
- Does hex accept both uppercase and lowercase?
- Yes, both are accepted. Output digits are always shown lowercase.
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