Encode bytes with a self-identifying multibase prefix, or detect the prefix and decode an existing multibase string.
Runs in your browser — your input is processed on this device and never uploaded.
Enter text or upload a file to encode. To decode, enter the encoded text.
Used only when encoding. Decoding detects the base from its prefix.
Results appear here.
Multibase puts one character in front of encoded data to say which base and alphabet follow, so a decoder needs no separate setting. The specification comes from the Multiformats project, and IPFS content identifiers are its best-known users.
| Prefix | Base | Alphabet |
|---|---|---|
| 0 | base2 | Binary digits |
| f | base16 | Lowercase hexadecimal |
| b | base32 | RFC 4648 Base32, lowercase, no padding |
| k | base36 | 0-9 and a-z |
| m | base64 | RFC 4648 Base64, no padding |
| u | base64url | URL-safe Base64, no padding |
A bare string such as 3q2+7w could be Base64 or something else, and guessing wrong decodes to garbage without an error. A one-character prefix makes the string self-describing, so systems that pass identifiers around, such as IPFS, can change their preferred base without breaking older values.
Base64, Base32 and Hex produce the same alphabets without the prefix, for when the other side already knows the base. Base58 handles the base58btc form used by did:key identifiers (prefix z), which this page does not accept: decode the part after the z there.
The prefix is part of the value. Strip it and the string is no longer multibase, and a decoder can no longer tell which base it was.
Base256emoji and the two Base58 forms are left out on purpose. The emoji base does not round-trip reliably in the library this tool uses, and whole-buffer Base58 is better handled by the dedicated tool.
Warning
Encoding does not encrypt, compress, hash or authenticate the data.
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