Converter

Integer base converter

Convert integers between bases 2–64 without floating-point precision loss.

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Input

Result

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Using this tool

Convert signed integers between bases 2–64 using big integers rather than floating-point arithmetic.

Actions: Convert

Example

Convert base 16 to base 10: this value exceeds JavaScript safe integer precision but remains exact.

Example action and settings

Action: Convert
Input base: 16
Output base: 10

Input / action

ffffffffffffffff

Result / expected behavior

18446744073709551615

Available options: Input base · Output base

Scope and limitations

Only integers are accepted, with at most 10,000 characters after trimming.
The digit alphabet is 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ+/; bases above 36 are case-sensitive.

Common mistakes

Do not add a 0x prefix or confuse base-64 numerals with Base64 text encoding.

Related tools

Text to binary Roman numeral converter

Privacy and browser support

Input is processed in this browser. Do not use real keys or active sensitive credentials as demonstration data. Device features require browser support and your permission.