How do I use the number base converter?
- Enter the number (prefixes like 0x or 0b are fine).
- Choose the base it is written in.
- Read the value in every other base.
Number base converter: frequently asked questions
How do I convert decimal to binary?
Repeatedly divide by 2 and read the remainders from bottom to top, or just enter the number here.
What is hexadecimal used for?
Colours (#12D18E), memory addresses, byte values and IPv6, because each hex digit maps to exactly 4 bits.
Does it handle very large numbers?
Yes. It uses arbitrary-precision integers, so there is no rounding.
Can I convert negative numbers or fractions?
Not at the moment; enter a whole, non-negative number.
Can I use 0x and 0b prefixes?
Yes. They are removed automatically.
Why is the binary grouped in fours?
Groups of four bits (nibbles) map to one hex digit, which makes binary easier to read.
What is octal used for?
Mostly Unix file permissions, such as 755. See our chmod calculator.
Is anything sent to a server?
No. It runs in your browser.
Is there an API for this tool?
Selected tools are available through a rate-limited public API. Contact us if you need higher volumes.
Is the number base converter free?
Yes. It is free with no sign-up and no usage limits for normal use.