Number Base Converter
Enter a number in any base and instantly see it in binary, octal, decimal and hexadecimal. Uses big integers so large values convert without precision loss, with grouped binary for readability.
About this tool
Number base conversion is a constant chore in low-level work — reading a hex color, decoding a permission bitmask, or checking a byte in binary. This converter takes a number in any base and shows it simultaneously in binary, octal, decimal, and hexadecimal, so you can move between representations without reaching for a manual calculation.
Under the hood it uses big-integer arithmetic, which means very large values convert without the precision loss you get from floating-point tricks. The binary output is grouped for readability, making it easy to spot individual bits when you are working with flags, masks, or memory addresses.
How to use
- Enter a number in whichever base you have — binary, octal, decimal, or hexadecimal.
- Read the equivalent value instantly rendered in all four bases.
- Use the grouped binary output to inspect individual bits at a glance.
- Convert very large numbers without worrying about rounding, thanks to big-integer math.
- Copy the representation you need into your code, calculator, or documentation.
- Clear the field and enter a new value to convert again.
Features
- Simultaneous conversion across binary, octal, decimal, and hexadecimal from a single input.
- Big-integer arithmetic so large values convert exactly, with no floating-point precision loss.
- Grouped binary output that makes individual bits and bytes easy to read.
- Accepts input in any of the four bases and figures out the rest for you.
- Ideal for bitmasks, color values, memory offsets, and low-level debugging.
- Runs entirely in your browser, so conversions are instant and fully offline.
Frequently asked questions
Can it handle very large numbers without losing precision?
Yes. The converter uses big-integer arithmetic rather than floating-point, so even numbers far larger than a 64-bit integer convert exactly across all four bases.
Is any of my input sent to a server?
No. All conversion happens locally in your browser. The numbers you type never leave your device.
Why is the binary output split into groups?
Grouping bits (for example into nibbles or bytes) makes long binary strings far easier to read and helps you locate a specific bit when working with flags and masks.
Which bases can I convert between?
The tool handles the four most common bases in programming: binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16), all at once.
How do I convert a hex color to decimal RGB?
Enter each two-character hex component here to see its decimal value, or paste the whole hex number to read it in decimal — useful when translating a color code into RGB channel values.