Number Base Converter
Enter a number in binary, octal, decimal, or hexadecimal and see it in all four bases at once — with the decimal-to-binary conversion steps shown for your number.
Input base
Frequently Asked Questions
- How do I convert a number between bases?
- Enter your number, pick which base it is written in (binary, octal, decimal, or hexadecimal), and the tool instantly shows its value in all four bases at once.
- How does decimal to binary conversion work?
- Divide the decimal number by 2 repeatedly, recording each remainder. Reading the remainders from last to first gives the binary digits. The tool shows these exact division steps for your number.
- How large a number can I convert?
- Up to 9007199254740991 (JavaScript's largest safe integer). Conversions use exact integer arithmetic, so every digit is precise across all four bases.
- What digits are valid in each base?
- Binary uses 0-1, octal uses 0-7, decimal uses 0-9, and hexadecimal uses 0-9 plus A-F. The tool flags any digit that is not valid in the base you picked.
- Is my number sent to a server?
- No. All conversions run entirely in your browser — nothing you enter ever leaves your device.