Base85 / Ascii85 Encoder & Decoder

Base85 is a binary-to-text encoding: it represents bytes with printable characters, rather than encrypting them. This Base85 encoder and decoder converts UTF-8 text in your browser, so the text you enter stays on your device.

Each complete group of 4 bytes becomes 5 Base85 characters. That makes Base85 more compact than Base64 for the same binary data: Base64 turns 3 bytes into 4 characters, while Base85 turns 4 bytes into 5. Internally, each 4-byte group is treated as a 32-bit number and written in base 85.

Select the variant that matches the data source. Adobe Ascii85 is common in PostScript and PDF. This tool encloses newly encoded Ascii85 in <~ and ~>, accepts framed or unframed Ascii85 when decoding, and recognizes z as four zero bytes. ZeroMQ Z85 has its own 85-character alphabet, with no Ascii85 framing or z shortcut; its input must be a multiple of 4 bytes when encoding and a multiple of 5 characters when decoding.

Ascii85 and Z85 are related Base85 variants, but their alphabets are not interchangeable. Choose Adobe Ascii85 when the source contains <~ ~>, comes from a PDF or PostScript workflow, or documents the Ascii85 format. Choose Z85 only when the protocol, library, or data producer explicitly specifies ZeroMQ Z85.

If decoding fails, first verify the selected variant and preserve the original characters. Ascii85 permits whitespace and may include its delimiters; Z85 output must contain full 5-character groups. A value encoded with one variant cannot be reliably decoded with the other.

Base85 makes binary data easier to store or transfer through text-oriented systems, but it does not conceal the content. Anyone with the matching variant can decode it without a password or secret key. Use encryption separately when confidentiality or access control is required.