Number Base Converter

What is a Number Base Converter?

A Number Base Converter translates numbers between the four counting systems used in programming: binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16). Type a value, choose which base it is written in, and the tool shows all four representations at once — handy for color values, permission masks, memory addresses and bit-level work.

Why do large numbers stay exact?

The converter uses your browser's arbitrary-precision number type instead of floating-point math. Even values far beyond JavaScript's normal safe range convert digit-for-digit accurately and never round.

When is each base used?

• Binary (0, 1): bits, masks and bitwise operations in low-level programming.
• Octal (0–7): classic Unix file permission masks used with chmod.
• Decimal: ordinary everyday numbers.
• Hexadecimal (0–9, A–F): CSS colors such as #FF8800, memory addresses and byte values.

Is my data safe?

Yes. All conversions run in your browser; the number you type is never sent or stored. Free, no signup and no install.

How to use Number Base Converter

Type a number, choose its base, and see binary, octal, decimal and hexadecimal side by side.

Use the controls above to provide your input or choose options, then review the result on the page.

Why use our Number Base Converter

• Converts numbers between binary, octal, decimal and hexadecimal instantly in your browser.
• Complete the task with a focused Number Base Converter workflow instead of switching between apps.
• Open it in your browser and get started—no account or installation required.