Dev Tools
Number Base Converter
The Number Base Converter converts a number between binary, octal, decimal, and hexadecimal, updating all four fields live as you type in any one of them. It's a handy reference for developers working with bitmasks, color codes, or low-level data, and for students learning how number systems relate to each other.
Every conversion is calculated instantly in your browser using plain JavaScript math, so the numbers you enter are never sent to a server for processing.
How to Use the Number Base Converter
- Open the Number Base Converter tool.
- Type a number into any one of the base fields — binary, octal, decimal, or hex.
- Watch the other three fields update automatically.
- Copy the value you need in the base you need it in.
Frequently Asked Questions
What happens if I type an invalid character for the selected base, like an 8 in binary?
The tool will flag or ignore characters that aren't valid for that base, since binary only allows 0 and 1, octal only allows 0-7, and so on.
Can it handle negative numbers or very large numbers?
It's built for standard positive integers within typical JavaScript numeric precision; extremely large numbers beyond safe integer limits may lose precision.
Does this tool store or transmit the numbers I convert?
No, all conversions happen locally in your browser and nothing is sent to a server or saved anywhere.