Number Base Converter
Enter a value and pick its base to see it in binary, octal, decimal, and hexadecimal.
Convert a whole number between binary, octal, decimal, and hexadecimal in one step. Choose the base your value is written in, type it in, and see it rendered in all four bases at once. The converter checks that every digit is legal for the base you picked and uses arbitrary precision arithmetic, so even very large numbers convert exactly with no rounding.
How to use
- Pick the source base of your number: binary, octal, decimal, or hexadecimal.
- Type or paste the value into the Value field. Underscores and spaces are ignored, and a leading minus sign is allowed.
- Read the result in all four bases in the results panel below.
- Use the Copy button next to any row to copy that value.
- Press Reset to clear the field and start again.
Examples
- Decimal 255 converts to binary 11111111, octal 377, and hexadecimal FF.
- Hexadecimal FF converts to decimal 255 and binary 11111111 (the source base is read case insensitively).
- Binary 1010 converts to decimal 10 and hexadecimal A.
FAQs
- Which bases can I convert between?
- Binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). You choose one as the source and the tool shows the value in all four at once.
- Can it handle very large numbers?
- Yes. The converter uses BigInt arithmetic, so integers far beyond the usual 64 bit limit convert exactly with no precision loss or rounding.
- Why am I getting an invalid number error?
- The error means a digit is not legal for the base you selected. For example the digit 2 is not valid in binary, and the letter G is not valid in hexadecimal. Check the value against the chosen base.
- Does it support negative numbers and decimals?
- Negative whole numbers are supported with a leading minus sign. Fractional values (numbers with a decimal point) are not supported, since this tool converts integers only.
- Are letters in hexadecimal case sensitive?
- No. You can enter hexadecimal input in upper or lower case. The hexadecimal output is shown in upper case for readability.
- Does my input get sent anywhere?
- No. The conversion runs entirely in your browser. Nothing you type is uploaded or stored.
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