Base 36 Converter

Base36 is a positional numeral system that uses 36 unique symbols to represent numbers: the digits 0 through 9 and the uppercase letters A through Z, where A represents 10, B represents 11, and so on up to Z representing 35. Base36 is the most compact case-insensitive alphanumeric numeral system using standard ASCII characters. This means every character in a Base36 string can be typed using only one hand on a standard keyboard, and the result remains readable and unambiguous.

The appeal of Base36 lies in its balance between compactness and readability. A Base36 number can represent large values using relatively few characters while remaining human-readable without any special tools. For example, the decimal number 1,000,000 is represented as 'LFLS' in Base36 — just four characters instead of seven. This compactness makes Base36 extremely useful for generating short unique identifiers, URL shorteners, and compact serial numbers.

This converter supports bidirectional conversion between decimal and Base36. It also displays the number in seven different bases simultaneously — binary, octal, decimal, duodecimal, hexadecimal, vigesimal, and Base36 — giving you a comprehensive view of how the same quantity appears across different numeral systems.

Converting between decimal and Base36 uses the standard algorithm for base conversion: repeated division by 36, collecting remainders at each step.

Understanding the mapping between Base36 characters and their numeric values is essential for manual conversion and debugging.

The Base36 converter provides two conversion directions and a comprehensive multi-base display:

1. Choose the conversion direction: Click "Decimal → Base 36" or "Base 36 → Decimal" to set the mode.
2. Enter the number: Type a decimal number (digits 0-9) or a Base36 value (digits 0-9 and letters A-Z) into the input field.
3. View the result: The converted value appears in the result field. Additionally, the "All Base Representations" section shows the number in binary, octal, decimal, duodecimal, hexadecimal, vigesimal, and Base36 simultaneously.

Invalid input is automatically detected and flagged with an error message.

Base36 is widely used in URL shorteners and compact identifier generation. Services like bit.ly, t.co, and tinyurl use Base36 (or its case-sensitive cousin Base62) to encode database record IDs into short, readable URLs. A Base36 encoding of a 32-bit integer produces at most 7 characters, compared to 10 digits in decimal, making URLs significantly shorter and more user-friendly.

In software development, Base36 is useful for generating human-readable unique identifiers. Session tokens, invitation codes, and short reference numbers often use Base36 to achieve a balance between security (many possible values) and usability (short enough to type or read aloud over the phone).

Data serialization and storage applications sometimes use Base36 to compress numeric values. MongoDB, for example, uses a Base62 variant for its short identifiers, and similar approaches with Base36 appear in various database systems and file naming conventions where compactness and readability are both important.