Base36 Converter
Convert a decimal number or text to Base36 and back - 1234567890 ↔ kf12oi.
Base36 Converter
Convert a decimal number or plain text to Base36 (digits 0–9 and letters a–z) and back. Base36 is a compact way to write large numbers, common for short IDs and codes.
kf12oi-kf12oi.
About Base36 Converter
The Base36 Converter turns a decimal number into Base36 - using digits 0–9 and letters a–z - and back to decimal. It also converts plain text: the text is read as UTF-8 bytes, so 623285 becomes l4ex033g5 and back. Base36 packs large values into short, URL-safe strings, which is why it is popular for compact IDs and codes. It uses BigInt, so values of any size stay exact.
How to use Base36 Converter
- Choose a direction: Decimal → Base36, Base36 → Decimal, Text → Base36 or Base36 → Text.
- Type or paste the value.
- Optionally list characters to ignore, such as "-", to convert each part of an ID separately.
- Copy the converted result.
Frequently asked questions
What is Base36?
Base36 is a positional numeral system that represents numbers with 36 characters - the digits 0–9 and the letters a–z - so large numbers become much shorter than in decimal.
How is Base36 different from Base64?
Base36 encodes numbers using a case-insensitive alphanumeric alphabet, which is convenient for short IDs. Base64 encodes arbitrary binary data using 64 characters, including symbols. They serve different purposes.
Does it work with very large numbers?
Yes. The converter uses BigInt, so it handles numbers of any size without losing precision.
What is the difference between the number and the text modes?
The number modes treat the value as one big number, so l4ex033g5 becomes 59589235193909. The text modes read the value as UTF-8 bytes, so the same l4ex033g5 becomes the text 623285. Both are correct - they answer different questions.
Can I convert an ID that contains dashes?
Yes. Put the separator - for example "-" - into the "Ignore characters" field. The value is split on it, every part is converted on its own and the separators stay in place, so kf12oi-16 becomes 1234567890-42.