How to use the Base32 encoder and decoder
Paste text or Base32 into Input, choose Auto-detect, Encode, or Decode under Mode, and read the result in Output. Encode turns the input into RFC 4648 Base32. Decode turns a valid Base32 value back into UTF-8 text. Auto-detect checks for a canonical Base32 value before it chooses a direction.
Encode text to Base32 step by step
- Enter text or Base32 in Input.
- Click Upload to load a text file into Input.
- Select Auto-detect, Encode, or Decode under Mode.
- Read the result in Output, then use Copy or Download.
How Auto-detect decodes Base32 text
When checking a possible Base32 value, Auto-detect removes whitespace, checks the RFC 4648 alphabet, padding, length, and unused final bits, then tests a decode and re-encode round trip. Input that passes those checks is decoded. Other input is encoded as text, so Hello becomes Base32.
Input: Hello
Output: JBSWY3DPChoose Encode or Decode when the direction is known. A word can contain only Base32 characters by coincidence, and a Base32 value can look like ordinary letters.
RFC 4648 Base32 input and output rules
Encode reads Input as UTF-8 and writes uppercase letters A-Z plus digits 2-7. It adds = padding when needed. Decode accepts uppercase or lowercase Base32, removes whitespace, checks supplied padding, and returns UTF-8 text.
Input: JBSWY3DP
Output: HelloCharacters such as 0, 1, 8, and 9 are invalid Base32 characters. Invalid lengths, padding, or final bits produce an error and clear Output. Empty Input clears Output and the status message. If decoded bytes are not valid UTF-8, the browser's TextDecoder can display replacement characters.
Load, copy, and download Base32 text
Upload accepts files marked as .txt, .csv, .log, .md, or text/plain in the file picker. The conversion code processes text input and defines no binary conversion or file-size limit.
Copy places the current Output value on the clipboard when that action is available. Download saves that value as base32-encoder-decoder-output.txt. The page does not provide a filename field.
When to choose another text converter
Use this page for RFC 4648 Base32. The Text Conversion Tools category includes related formats. Choose Base64 Encoder / Decoder for standard or URL-safe Base64. Choose Text Code Converter for decimal, hexadecimal, binary, or octal character codes.
Where Base32 conversion comes up
Encode a UTF-8 label before placing it in a field that expects RFC 4648 Base32, then copy the uppercase result with Copy.
To check a stored Base32 value, paste it into Input, select Decode, and compare the returned UTF-8 text with the original label.
Load a support note or test fixture with Upload, convert it in the selected Mode, and save the result with Download.
Frequently asked questions
What is Base32 encoding?
Base32 encoding represents UTF-8 bytes with the RFC 4648 alphabet of A-Z and 2-7. This page writes uppercase output and can add trailing = padding.
How do I decode Base32 text?
Paste the value into Input and select Decode under Mode. Output shows the decoded UTF-8 text. The status area reports an error when the alphabet, padding, length, or final bits are invalid.
Can the Base32 decoder read lowercase letters and spaces?
Yes. Decode changes letters to uppercase and removes whitespace before validating the Base32 value. It rejects characters outside A-Z and 2-7, along with invalid padding.
Why does Auto-detect encode some text instead of decoding it?
Auto-detect decodes only input that passes the canonical RFC 4648 checks and round-trip test. Text such as Hello fails that Base32 test, so the mode encodes it.