Number Base Converter

Convert numbers between binary, octal, decimal, and hexadecimal instantly. Powered by BigInt for large values.

Programmers working with bitmasks, colour codes, and low-level data.

How to use it

  1. Type in any base

    Enter a value into the binary, octal, decimal, or hex field.

  2. See all bases

    The other three fields update instantly with the equivalent value.

  3. Copy a value

    Click the copy icon next to the base you need.

Why use this tool?

Working with binary, octal, and hexadecimal is routine in low-level programming, but mental conversion is slow and error-prone. This tool converts a number across all four bases at once, using BigInt so even very large numbers stay exact.

Common use cases

Bitmasks & flags

Convert binary flag values to hex and decimal while coding.

Colour & encoding work

Translate hex colour or byte values into decimal and binary.

Learning CS

Understand how the same number is represented across number systems.

Frequently asked questions

How large a number can it handle?

It uses JavaScript BigInt, so it stays accurate for numbers far beyond the normal 64-bit range.

Does it support negative numbers?

It is designed for non-negative whole numbers across bases.

Is the conversion done online?

No. It runs entirely in your browser.

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