Number Base Converter
Developer toolNewConvert numbers between binary, octal, decimal and hex.
This tool runs entirely in your browser. Your files never leave your device — nothing is uploaded.
Enter a number on the left to see it in binary, octal, decimal and hex.
Frequently asked questions
Which number bases can I convert between?
This tool converts whole numbers between binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16). Just enter a value, pick its input base, and all four representations appear instantly with a copy button for each.
Is my data uploaded or stored anywhere?
No. Every conversion runs entirely in your browser using JavaScript, so the numbers you enter never leave your device. There are no servers, uploads, accounts or logs involved, which makes it safe for sensitive values.
Why does it show an error for some inputs?
Each base only allows certain digits — binary accepts 0 and 1, octal 0 to 7, and hexadecimal 0-9 plus A-F. If you enter a digit that is not valid for the input base you selected (for example the digit 2 in a binary number), the tool flags it instead of silently returning a wrong result.