Binary / Hex Converter
Reading a hex dump or writing a bitmask? Type in binary, octal, decimal, or hex — the penguin translates to all four bases live, as you type.
How to use
- Type into any field. Binary, octal, decimal, or hex — whichever you've got.
- Watch the other three update. Conversion happens live with every keystroke.
- Mind the red flag. If a digit doesn't belong in that base (like 2 in binary), you'll get a friendly nudge instead of a wrong answer.
- Copy the set. "Copy all" grabs all four representations in one go — handy for docs and comments.
Frequently asked questions
How do I convert binary to hex?
Type your binary number into the Binary field — the Hex field updates instantly. For example, 11111111 becomes FF. Each group of 4 binary digits maps to exactly one hex digit, which is why hex is the go-to shorthand for binary.
Which number bases are supported?
Four: binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Type into any one and the other three convert automatically.
Why is my input marked as invalid?
Every base has its own allowed digits — binary only accepts 0 and 1, octal 0–7, decimal 0–9, hex 0–9 plus A–F. If a digit doesn't belong (like 9 in octal or G in hex), the converter tells you instead of guessing.
Does it handle really large numbers?
Yes. The converter uses arbitrary-precision integers, so there's no 32-bit or 64-bit ceiling — paste a 256-bit hash and it'll convert the whole thing without rounding.
What about negative numbers?
Type a minus sign in any field (e.g. -1010 in binary or -A in hex) and all four bases show the negative value. Note this is sign-magnitude notation, not two's complement — it answers "what number is this" rather than "how is it stored."
Related tools
Keep the momentum going.