Free Base32 encoder and decoder (RFC 4648). Convert text to Base32 using the A-Z2-7 alphabet with optional padding, or decode Base32 back to text. Runs entirely in your browser, no data uploaded.
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How base32 encoder & decoder works
Base32 (RFC 4648) is a binary-to-text encoding that represents every 5 bytes of input as 8 characters from a 32-symbol alphabet (A-Z and 2-7). It is about 20% larger than the original. Because the alphabet is uppercase letters plus digits and excludes ambiguous characters (0/O, 1/I/L), Base32 is ideal for case-insensitive systems and human transcription.
This tool encodes your text into Base32 using the standard A-Z2-7 alphabet. The padding option adds "=" characters so the output length is always a multiple of 8 (the RFC default); turn it off to drop padding. Decoding ignores whitespace and case, strips trailing padding, and reconstructs the original bytes.
Base32 is widely used for TOTP / HOTP authenticator secrets, DNSSEC, and encoded keys that humans may need to read or type. It is an encoding, not encryption — it provides no security. All processing happens in your browser using built-in UTF-8 conversion.
Frequently asked questions
Why does Base32 use only A-Z and 2-7?
The 32 symbols are chosen to be unambiguous for humans and case-insensitive systems. The digits 0, 1, 8, and 9 are excluded to avoid confusion with O, I, L, B and other letters, which makes Base32 safer to transcribe by hand than Base64.
What is the padding for?
RFC 4648 pads the output with "=" characters so the encoded length is always a multiple of 8. Most decoders require or tolerate it; you can toggle padding off if your target system does not want trailing "=" characters.
Is Base32 the same as Base64?
No. Base64 uses a 64-symbol alphabet (A-Z, a-z, 0-9, +, /) and encodes 3 bytes as 4 characters (33% overhead). Base32 uses a 32-symbol alphabet, is case-insensitive, and encodes 5 bytes as 8 characters (60% overhead). Choose Base32 for human readability and case-insensitive systems.
Can I decode lowercase Base32?
Yes. The decoder uppercases the input before decoding, so lowercase and mixed-case Base32 both decode correctly. Whitespace is also stripped, so you can paste wrapped or spaced Base32.
