Number base converter

Convert signed integers exactly between bases 2–36, including values larger than JavaScript’s safe integer range.

Your input

Outputs are cleared when the input changes.

Result

Enter your data or use the example, then run the tool.

Worked example

FF in base 16 is 255 in base 10 and 11111111 in base 2.

9007199254740993 can be converted and converted back without passing through Number.

Method

Validate every digit against the selected base and accumulate the integer using BigInt multiply-and-add.

Repeated division and remainders produce target digits. A leading minus applies to the entire integer; no machine word width is assumed.

Limits

Integers only, with at most 1,000 input digits. No fractions, decimal points, scientific notation, separators or expressions.

No two’s-complement interpretation and no prefix inference. Upper- and lowercase letters are equivalent.

Sources

MDN: BigInt integer arithmetic

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