Number Base Converter — Binary, Octal, Decimal & Hex
Convert numbers between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) instantly. Enter a number in any base and see all four equivalents at once. Useful for programming, computer science study, and working with low-level data. Free, no signup.
Three steps. No setup.
Drop your content into the field above, or type directly into it. The tool starts working the moment you do — no button to press.
Everything is calculated locally in your browser as you type. No waiting, no uploading, no server involved.
Hit Copy to grab the result, or Download if the tool offers a file. Close the tab — nothing is stored.
Free, private, and built to last.
Number Base Converter is a free online tool that runs entirely in your browser. No data is sent to any server — your input stays private on your device and disappears the moment you close the tab.
It is designed to be fast, simple, and accessible to everyone — whether you are a developer, marketer, student, or business owner. No signup, no ads, no nonsense. Just the tool, ready when you need it.
Frequently Asked Questions
Select 'Binary' as your input base, enter your binary number (using only 0s and 1s), and the decimal equivalent appears instantly. For example, binary 11111111 converts to decimal 255.
Hexadecimal (hex) is used in programming, web design (color codes like #FF5733), memory addresses, and network protocols. It is a compact way to represent binary data — one hex digit represents exactly four binary digits.
Binary (base 2) uses only 0 and 1. Octal (base 8) uses digits 0–7. Decimal (base 10) is the standard number system using 0–9. Hexadecimal (base 16) uses 0–9 and A–F. Computers work in binary internally but hex is used as shorthand because it converts cleanly.
Yes. Select 'Decimal' as your input base, enter any whole number, and the hexadecimal (and binary and octal) equivalents appear automatically. For example, decimal 255 converts to hex FF.
The converter handles numbers within JavaScript's safe integer range (up to 2^53 − 1, or about 9 quadrillion in decimal). For most practical use cases in programming and computer science, this range is more than sufficient.