About Base85 / Ascii85 Encoding
Base85 encodes binary data using 85 printable ASCII characters. Every group of 4 bytes becomes 5 characters — making it ~25% more efficient than Base64. It's widely used in PDF files, PostScript, and ZeroMQ message framing.
Ascii85 (Standard)
Character set: ! to u (85 chars). Uses <~ and ~> delimiters. Special z shortcut for all-zero groups. Used in Adobe PDF and PostScript.
Z85 (ZeroMQ)
Uses a different safe character set that avoids quotes and backslashes. Designed for embedding in source code strings. Input must be a multiple of 4 bytes (encode) or 5 chars (decode).
Frequently Asked Questions
What is Base85 / Ascii85 encoding?
Base85 (also called Ascii85) is a binary-to-text encoding scheme that encodes every 4 bytes of binary data as 5 printable ASCII characters, achieving ~25% smaller output than Base64.
What is the difference between Ascii85 and Z85?
Ascii85 uses characters in the range !–u (plus a special z compression shortcut). Z85 (ZeroMQ variant) uses a different character set designed to be safe in source code strings, avoiding backslash and quote characters.
Is my data sent to a server?
No. All encoding and decoding happens entirely in your browser using JavaScript. No data is transmitted to any server.
What are common uses for Base85?
Base85 is used in PDF files, PostScript, ZeroMQ message framing, Git binary patches, and anywhere a compact ASCII representation of binary data is needed.