Base-36 Converter -

const num = 1337; const base36 = num.toString(36); // "y5" const parsed = parseInt("y5", 36); // 1337 So if you don’t need custom validation or edge-case handling, the built-in methods work perfectly.

const decoded = fromBase36(base36); console.log( Base-36 ${base36} = decimal ${decoded} );

function toBase36(num) { if (num === 0) return "0"; let result = ""; const digits = "0123456789abcdefghijklmnopqrstuvwxyz"; let value = num; while (value > 0) { result = digits[value % 36] + result; value = Math.floor(value / 36); } return result; } function fromBase36(str) { const digits = "0123456789abcdefghijklmnopqrstuvwxyz"; let result = 0; for (let i = 0; i < str.length; i++) { const char = str[i].toLowerCase(); const value = digits.indexOf(char); if (value === -1) throw new Error( Invalid base-36 character: ${str[i]} ); result = result * 36 + value; } return result; }

// Example usage: const decimal = 123456789; const base36 = toBase36(decimal); console.log( Decimal ${decimal} = base-36 ${base36} );