Category: Developer tools
Number Base Converter
Convert numbers between binary, octal, decimal and hex
Convert a number between binary, octal, decimal, hexadecimal or any custom base from 2 to 36, entirely in your browser.
Everything on this page is processed in your browser. Nothing is uploaded.
What this tool does
Programmers switch between number bases constantly: binary for bit flags, hexadecimal for colours and memory addresses, octal for Unix file permissions. This converter parses the input in the base you choose — accepting 0x, 0o and 0b prefixes — and shows the same value in every other common base at once, with optional digit grouping for readability.
How to use it
- Type a number and choose the base it is written in.
- Use Custom base for anything from base 2 to base 36.
- Read the converted value in binary, octal, decimal and hexadecimal.
Privacy
This tool runs entirely in your browser. Your input is never uploaded, stored or shared — closing the tab removes it.
Frequently asked questions
- Can it handle negative numbers?
- Yes. A leading minus sign is preserved through the conversion in every base.
- How large a number can it convert?
- Values are handled as arbitrary-precision integers, so there is no practical size limit like there would be with ordinary 32-bit or 64-bit arithmetic.
- What do the 0x, 0o and 0b prefixes mean?
- They are common shorthand for hexadecimal, octal and binary respectively. The converter recognises them automatically when the matching base is selected.