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About this tool
Encode text to Base32 (RFC 4648) or decode Base32 back to text, right in your browser.
This Base32 encoder converts text to RFC 4648 Base32 using the standard A-Z and 2-7 alphabet, reading your input as UTF-8 so accented characters and emoji encode correctly. It packs the byte stream five bits at a time, pads the result with = to a multiple of 8 characters, and lets you switch to the lowercase alphabet or wrap the output at a fixed line length. It is for developers who need a case-insensitive, transcription-safe encoding of a value and want to see the byte count, padding count and size overhead alongside the result.
Open Base32 Encoder / Decoder on AltFTool — it loads instantly in your browser.
Type or paste your text into the 'Input' box (up to 10,000 characters, tracked by the live counter under the field) — this tool only encodes, and the Base32 result appears in the 'Output' panel as you type. 'Clear' empties the box.
Under 'Encoding Options' set 'Alphabet Case' to 'Uppercase (A–Z)' or 'Lowercase (a–z)', set 'Padding' to 'With Padding' or 'Without Padding', and optionally put a number from 0 to 512 in 'Line Length (Optional)' to wrap the output — 0 for no wrap.
Click 'Encode to Base32' to scroll to the output, where the button flashes 'Encoded!' and the status row reads 'Encoded successfully!' with the processing time; then use 'Copy' or 'Download' to save the result as base32-output.txt.
Turn the = padding off for systems that reject it, and switch the whole alphabet to lowercase, without editing the output by hand.
Input goes through TextEncoder first, so a multi-byte character or emoji becomes its real UTF-8 bytes rather than being mangled or dropped.
Alongside the output you get the source byte length, the encoded length, the number of padding characters, and the percentage size change.
The 32 symbols A through Z followed by the digits 2 through 7, with = as padding. The digits 0, 1 and 8 are deliberately left out because they are easily confused with O, I and B when read or typed.
About 60 percent. Every 5 bytes of input become 8 Base32 characters, so 5 bytes in gives 8 characters out — noticeably larger than Base64, which produces 4 characters per 3 bytes for roughly 33 percent overhead.
Because the encoded length was not a multiple of 8. Padding fills it out to the next multiple, which is why you commonly see 1, 3, 4 or 6 = characters at the end. You can switch padding off if the receiving system does not want it.
Use Base64 when size matters and the value only ever moves between machines. Use Base32 when a human has to read, type, or dictate the value, or when the transport is case-insensitive, since Base32 uses one case and avoids ambiguous characters.