Number Base Converter
Convert a number between binary, octal, decimal, hex and any base (2–36). Runs entirely in your browser.
Base
How it works
1
Enter a number
Type a number, optionally with a 0x, 0b or 0o prefix.
2
Pick the input base
Choose the base it’s in, or let auto-detect read the prefix.
3
See every base
Binary, octal, decimal and hexadecimal update instantly.
4
Custom base
Convert to any base from 2 to 36, and copy the result.
Frequently Asked Questions
Binary (2), octal (8), decimal (10), hexadecimal (16), and any custom base from 2 to 36.
Yes — it uses BigInt, so large integers convert exactly without precision loss.
No — conversion runs in your browser.
Convert numbers between bases online for free. Enter a value in binary, octal, decimal or hexadecimal — or with a 0x, 0b or 0o prefix and auto-detect — and instantly see it in every common base, plus any custom base from 2 to 36. It uses BigInt so even very large integers convert exactly. It’s ideal for programming, bit-twiddling and working with colours or memory addresses, and everything runs in your browser.