Base32 エンコード / デコード

What Is Base32 Encode / Decode?

Base32 is a binary-to-text encoding scheme defined in RFC 4648 that converts binary data into a string of 32 safe ASCII characters: the uppercase letters A–Z and the digits 2–7. Because the Base32 alphabet avoids lowercase letters, symbols, and ambiguous characters (0, 1, 8, 9), Base32-encoded strings are safe for case-insensitive file systems, DNS labels, and URLs without percent-encoding. Base32 encoding is widely used in TOTP (time-based one-time password) secret keys, content-addressed storage, and distributed systems that require human-copyable identifiers.

How to Use Base32 Encode / Decode

1. Select the Encode tab to convert plain text to Base32, or the Decode tab to convert Base32 back to text.
2. Paste or type your input into the text area.
3. The result appears instantly in the output panel below.
4. Click Copy to copy the result to your clipboard, or Swap to use the output as new input.

Features

• Encode plain text to Base32 (RFC 4648 standard alphabet)
• Decode Base32 strings back to readable text, case-insensitive
• Handles full UTF-8 character set including Unicode and emoji
• Swap output as input for chained encode/decode operations
• Copy result to clipboard in one click
• Runs entirely in your browser — zero data uploaded

FAQ

What is Base32 encoding?

Base32 is a binary-to-text encoding scheme defined in RFC 4648. It represents arbitrary binary data using a 32-character alphabet (A–Z and 2–7). Base32 is more compact than hex and safe for case-insensitive file systems and URLs, making it popular in TOTP secret keys, file hashing, and content-addressed storage.

What is the difference between Base32 and Base64?

Base64 uses 64 characters and produces shorter output, but includes characters (+, /, =) that require URL-encoding. Base32 uses only uppercase letters and digits 2–7, making it safer for case-insensitive systems and URLs without extra encoding. Base32 output is roughly 60% larger than the original data.

Is Base32 the same as encryption?

No. Base32 is an encoding scheme, not encryption. It is fully reversible without any key and provides no confidentiality. Do not use Base32 to protect sensitive data.

Is my data sent to a server?

No. All Base32 encoding and decoding happens entirely in your browser using a pure JavaScript implementation. No data is uploaded to any server.