Number Base Converter
Type a number and choose its base — the binary, octal, decimal and hexadecimal versions all update instantly.
About number bases
Computers work in binary, but programmers regularly switch between binary, octal, decimal and hexadecimal. This converter lets you type a value in any of those bases and instantly see it in all the others — handy for debugging, working with colors, bit masks or memory addresses.
How to use it
- Select the base of the number you’re entering.
- Type the value.
- Read the equivalents and copy any one you need.
Frequently asked questions
Which bases are supported?
Binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16) — the four most common in computing.
What is hexadecimal used for?
Hex is widely used in programming for colors (#ff0000), memory addresses and byte values, because each hex digit maps neatly to 4 binary bits.
Why is my input invalid?
Each base only allows certain digits — binary uses 0–1, octal 0–7, decimal 0–9, and hex 0–9 plus A–F. Check your input matches the chosen base.
Is it private?
Yes, everything runs in your browser.
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