Number Base Converter

Convert between binary, octal, decimal, and hexadecimal. All conversion runs in your browser.

Binary (base 2)

Octal (base 8)

Decimal (base 10)

Hexadecimal (base 16)

About this Number Base Converter

Developers constantly translate between binary, octal, decimal, and hex for bitmasks, colors, memory dumps, and network fields. Mistakes in base conversion cause subtle bugs.

This tool converts live as you type using BigInt so large values stay accurate.

How to use this tool

Type a value in any of the four base fields.
The other bases update automatically.
Copy the result you need into your code or docs.

Common use cases

Translate bit flags and permission masks
Convert hex dumps to decimal sizes
Check color and register values

FAQ

Is 0x prefix required for hex?

No. Enter digits only (A–F allowed). Prefixes are optional noise you can omit.

Privacy

All conversion runs in your browser. Read our Privacy Policy.