Number Base Converter
Convert a number between binary, octal, decimal, hexadecimal, or any custom base from 2 to 36 — handy for turning a hex color code or a memory address into decimal. 100% local processing in your browser (WebAssembly) — nothing is sent to a server.
How it works
The same number can be written differently depending on the base used: 255 in decimal is written ff in hexadecimal or 11111111 in binary. This is a very common need in development: a CSS color code like #1a2b3c, a memory address shown in hexadecimal in a debugger, or a binary flag in a network protocol often need to be converted to decimal (or the reverse) to be easily understood or compared. This tool also accepts any base between 2 and 36 for more specific cases.
Why choose "Custom…" for the base?
Beyond the four most common bases (binary, octal, decimal, hexadecimal), some use cases require an arbitrary base — for example base 36 (digits + letters a-z) used to generate short identifiers, or base 32 used in certain encodings. The "Custom…" option lets you enter any base between 2 and 36.
How is a negative number read in another base?
A - sign in front of the value is preserved as-is during conversion: the number's magnitude is converted to the target base, then the negative sign is reapplied to the final result, exactly as expected from a standard mathematical conversion.
Privacy: conversion runs entirely in your browser via WebAssembly — the value entered is never sent to a server.