Number Base Converter

What Number Base Converter does

Number Base Converter translates signed whole numbers between binary, octal, decimal, hexadecimal, and any custom base from 2 through 36. It is useful when reading protocol flags, permission masks, color-related values, database identifiers, bit fields, hardware registers, encoded examples, or programming exercises that represent the same integer in different ways. The tool shows the common bases side by side so you can compare the value without running separate commands.

The converter validates every character against the selected source base before producing output. For example, binary input can contain only 0 and 1, octal input can contain digits 0 through 7, and hexadecimal input can contain digits plus A through F. It accepts uppercase or lowercase letters, ignores surrounding whitespace, and supports an optional leading plus or minus sign. Invalid input is reported as a friendly status message instead of producing a misleading result.

Private browser-based workflow

All conversion happens with browser JavaScript and BigInt. No value is uploaded, logged, or sent to a server, which is helpful when checking identifiers, generated keys, debugging samples, or internal constants that should remain local. BigInt also means the tool is not limited to JavaScript's normal safe integer range, so large integer values can be represented accurately as long as they are whole numbers.

Practical tips

Use the quick buttons when you already know whether the input is binary, octal, decimal, or hexadecimal, then adjust the custom target base for less common formats. This tool intentionally does not support fractional numbers because precise fractional conversion requires additional rounding and representation choices. Always keep prefixes such as 0x or 0b out of the input field; choose the source base explicitly instead. If a converted value will be used in code, tests, permissions, or configuration, verify the expected base and sign before committing it.