Base85 Decode

Decode ASCII85 back to text, handling the Adobe delimiters and the z zero-group shorthand.

Base85 (ASCII85)
Text
Runs locally in your browser

About the Base85 Decode

This tool decodes Adobe ASCII85 to text. It accepts input with or without the <~ ~> delimiters, expands the z shorthand back into four zero bytes, and ignores whitespace so wrapped input from a PDF works. The decoded bytes are shown as UTF-8 text.

A character outside the ASCII85 range (printable ASCII from ! to u) is reported as an error. The usual culprit is a stray angle bracket left over from the delimiters, or a hyphen picked up when the stream was copied out of a diff. The final group deserves attention too: a tail of a single character is invalid, because one character cannot carry even one byte, so a truncated copy fails here rather than quietly producing a wrong byte.

Content pulled from a PDF is usually binary and often Flate-compressed on top of the ASCII85 layer, so readable text is the exception and noise is the norm. Treat the result as bytes and keep going: Zlib Decompress or Gzip Decompress is commonly the next step for a PDF stream. The Base85 Encode tool produces this format.

How to use

  1. Paste the ASCII85 string.
  2. Read the decoded text.
  3. Delimiters and z shorthand are handled for you.

Common questions

Do I need the delimiters?
No. The decoder works with or without <~ and ~>.
It says a character is invalid. Why?
ASCII85 uses only the printable range ! to u. A character outside it, or a stray letter, triggers the error.
Why is my decoded PDF data unreadable?
It is binary content, not text. ASCII85 in PDFs usually wraps compressed streams.