Number Base Converter
Binary, octal, decimal, hex and every base up to 36.
Runs entirely in your browser
Loading the tool…
| Decimal | — |
|---|---|
| Hexadecimal | — |
| Octal | — |
| Binary | — |
| Base 32 | — |
| Base 36 | — |
- —Bits
- —Bytes
- —Fits in
- —Parity
Any base from 2 to 36
Type a number in any base from 2 to 36 and read it back in all the others. Binary is grouped into bytes so long strings stay readable, and the panel shows how many bits the value needs and which fixed-width integer would hold it, which are the questions that usually prompted the conversion in the first place.
Prefixes and separators are accepted, so 0xFF, 1010 1010
and 1_000_000 all parse. Values up to 128 bits are supported; beyond that
the tool says so rather than silently wrapping around.
How to use it
- Enter your number and pick the base it is written in.
- Read the equivalents: decimal, binary, octal, hex and more.
- Use the custom base selector for anything unusual, up to base 36.
Questions
Why does hexadecimal use letters?
Hex is base 16, so it needs sixteen digit symbols. After 0–9 it borrows a–f for the values ten to fifteen. One hex digit is exactly four bits, which is why a byte is always two hex digits.
What is the 0x prefix for?
It is a convention telling a human or a compiler that what follows is hexadecimal, while 0b marks binary and 0o marks octal. They are not part of the number, and this tool strips them for you.
Can it convert negative or fractional numbers?
Not currently: it handles whole non-negative numbers up to 128 bits. Negative values depend on a representation choice (two's complement and its width) that a general converter cannot guess.
Your data stays on your device
Everything above runs inside your browser as WebAssembly compiled from Rust. Nothing you type is uploaded, logged or stored on a server. There is no server. You can load this page once, go offline, and it still works.