ToolWren › Number Base

Number Base Converter

Convert a number between binary, octal, decimal and hexadecimal. Enter a value, pick its base, and see all four at once.

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How to use the Number Base

Type your number into the Value field.
Select the base the number is currently in (binary, octal, decimal or hex).
The binary, octal, decimal and hexadecimal equivalents are shown together.
Change the value or base to convert again.

Privacy: this tool runs entirely in your browser. Your input is never sent to, received by, or stored on any server — there are no uploads and no tracking of what you enter.

About Number Base

Number bases

Binary (base 2) uses 0-1, octal (base 8) uses 0-7, decimal (base 10) is everyday numbers, and hexadecimal (base 16) uses 0-9 and A-F. Programmers switch between them constantly.

Why hex and binary matter

Hex is a compact way to write binary — each hex digit is exactly 4 bits. Colors, memory addresses and byte values are usually shown in hex.

How to use it

Type your number, choose the base it is currently in, and the tool shows the binary, octal, decimal and hex equivalents.

Frequently asked questions

What is hexadecimal used for?

Color codes, memory addresses, byte values and many programming contexts.

How many bits is one hex digit?

Exactly 4 bits, so two hex digits make one byte.

Can it convert negative numbers?

It focuses on non-negative integers; for negatives, consider two's complement representation.