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Number base converter
Convert exact signed integers between binary, octal, decimal, and hex.
02 / Your result
Your result will appear here.
Start with your own input or try an example.
What it does
Translate a whole number between the bases commonly used in code and technical notes. Select the input base and enter up to 1,024 digits to get binary, octal, decimal, and hexadecimal outputs together. BigInt arithmetic preserves exact values beyond the precision of ordinary JavaScript numbers.
Useful when
- Read a hexadecimal integer from a technical specification.
- Check binary and decimal representations while learning bit arithmetic.
- Convert a large numeric identifier without losing integer precision.
How to use it
- Select whether your input is binary, octal, decimal, or hexadecimal.
- Enter the digits with an optional sign, without base prefixes or separators.
- Convert, then copy all four values or download the conversion report.
A few useful details
Does this work beyond the safe JavaScript Number range?
Yes. Parsing and formatting use BigInt rather than floating-point Number arithmetic. Up to 1,024 input digits are supported, plus an optional leading plus or minus sign. The result remains an exact integer in all four bases.
How are negative numbers represented?
Outputs use a leading minus sign followed by the magnitude in each base. They are not fixed-width two’s complement bit patterns. Negative zero is normalized to zero, and leading zeroes are removed.
Can I paste 0x prefixes, fractions, or scientific notation?
No. Select the input base explicitly and paste only its digits with an optional sign. Base prefixes, embedded whitespace, digit separators, decimal points, and exponents are rejected. Uppercase and lowercase hexadecimal digits are accepted; output uses lowercase.