Number Base Converter
Convert numbers between binary, octal, decimal, hexadecimal or any base from 2 to 36 — even very large ones. Free, in your browser.
Separators are ignored — paste grouped literals like 0xDE_AD_BE_EF or 1010_1010.
—————🔒 Converted in your browser with arbitrary-precision math (bases 2–36) — nothing uploaded.
Convert between number bases
Type a number and its base and instantly see it in binary, octal, decimal and hexadecimal — plus any custom base from 2 to 36 — each with a copy button. It uses arbitrary-precision (BigInt) math, so it stays exact even for values far beyond what a normal calculator can handle. Everything runs locally in your browser.
Frequently asked questions
Can I convert to an unusual base like base 36?
Yes. Set the "from" base to anything from 2 to 36, and the custom-base row outputs any target base in the same range.
Does it handle very large numbers?
Yes. It uses BigInt arithmetic, so 64-bit and larger values convert exactly without rounding.
Can I use 0x or 0b prefixes?
Yes — a 0x prefix is accepted for hex and 0b for binary; you can also just type the raw digits.