Base-36 encode & decode

Client

Base-36 uses 0-9 and a-z (output is lowercase). This page encodes UTF-8 bytes as one big-endian integer—the same pattern as Base58 here, not Base58Check.

Part of encoding tools.

Workspace

Paste text, encode to base-36, or paste base-36 and decode—output replaces the field.

Base-36

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Treats UTF-8 bytes as one big-endian integer, then writes it in base 36 with digits 0-9 and a-z. Each leading 0x00 byte becomes one leading 0 in the string—same idea as Base58 on this site.

This is encoding only, not encryption. Not a single short integer API—always the full byte string.

Common use cases

  • Compare string length with Base32 or Base58 on the same UTF-8 paste.
  • Encode test byte patterns that include leading nulls (each becomes a leading 0 in base-36).
  • Decode pasted base-36 that was produced from raw bytes in another tool.

Common mistakes to avoid

  • Expecting a single decimal integer

    This page encodes the full UTF-8 byte sequence as one number in base 36—not a human-entered decimal to convert.

  • Confusing with encryption

    Base-36 is reversible encoding; anyone can decode the string.

FAQ

Why might the string be longer than Base64?

Base 36 is a smaller radix than Base64, so the digit string for the same integer is often longer.

Does data leave my browser?

No. Encoding runs entirely on your device.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • base 36 encode decode online
  • radix 36 0-9a-z text encoder
  • utf-8 to base36 browser
  • base36 leading zero bytes

More tools

Related utilities you can open in another tab—mostly client-side.