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Number base converter

Type a number in any of the four boxes, hexadecimal, binary, decimal or octal, and the other three update as you go. Copy any one of them.

It works on whole numbers of any size, using your browser's big integers, so a value too large for a normal number still converts exactly. Nothing is uploaded.

Whole numbers of any size, using your browser's big integers, so a value too large for an ordinary number still converts exactly.

Questions

Is what I paste sent anywhere?
No. Every tool in this kit runs in the page itself. There is no server here that receives what you paste, and you can check it in your browser's network tab: using a tool produces no request carrying your input at all.
How big a number can it handle?
Any whole number, however large. It uses BigInt, so a 256-bit hex value converts exactly rather than losing digits the way an ordinary number would past about 15 digits.
Does it do negative or fractional numbers?
Whole numbers, including negatives. Fractional values in other bases are ambiguous and rarely what people want here, so the tool sticks to integers and says so rather than rounding silently.
What counts as valid input?
Digits valid for that base: 0 and 1 for binary, 0 to 7 for octal, 0 to 9 for decimal, and 0 to 9 with a to f for hex. An invalid character is flagged rather than guessed at, so a typo does not turn into a wrong answer.

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