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Encoding

Decode Base85 (Ascii85) to text

Base85 Decode turns Ascii85 text back into the bytes it represents, the inverse of the Adobe encoding behind PostScript and PDF ASCII85Decode streams. Paste a block of characters drawn from ! to u and recover the original content as UTF-8 text. The decoder strips the <~ ~> delimiters that wrap PDF blocks when they are present and tolerates whitespace anywhere in the input, while characters outside ! to u (including the legacy z shorthand) stop the decode with Error: invalid base85. Every five input characters collapse back into four bytes. Developers use it to inspect PDF object streams and debug encoders.

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How to use Base85 Decode

  1. Open Base85 Decode in the Toolbox101 app.
  2. Paste the Ascii85 text to decode: with or without the <~ ~> delimiters that wrap PDF and PostScript streams.
  3. Read the Output box, which shows the recovered text as you type; 9jqo^ decodes to Man (with the trailing space).
  4. If a character falls outside ! to u, the Output box shows Error: invalid base85: a z from the legacy shorthand, or output from another Base85 variant such as Z85, will not decode here.
  5. Click Copy to take the decoded content and use it where you need it.

Worked example

Base85 Decode returns the output below for this input.

Input

<~9jqo^~>

Output

Man

Check it yourself: open Base85 Decode and enter the same input.

Frequently asked questions

What input does this Ascii85 decoder accept?

Anything within the strict Ascii85 alphabet ! to u, in groups of five characters per four output bytes. <~ ~> delimiters are stripped when present, and whitespace is ignored anywhere in the input, so a PDF block pasted verbatim decodes. Characters outside that range (including z, which Adobe's legacy shorthand uses for a zero group) are rejected with Error: invalid base85, as are groups whose value overflows 32 bits.

What does Ascii85-encoded text look like?

Ascii85 output uses only printable characters from ! to u, with no letters beyond lowercase u. The Adobe spec's own example is Man encoding to 9jqo^, and this page's worked example decodes that pair back. If a block contains characters above u, it was likely produced by a different Base85 variant such as Z85.

Is Base85 the same encoding as Base64?

No. Base64 writes 3 bytes as 4 characters using letters, digits, +, and /. Ascii85 writes 4 bytes as 5 characters from a different alphabet, so it is about 25 percent larger instead of 33 percent. Both are encodings, not encryption: either can be reversed without a key.

Why does the decoded output look garbled?

Ascii85 stores bytes, not necessarily text. If the original data was binary (image data or a compressed stream inside a PDF), the decoded result will not read as a UTF-8 message. Garbled output usually means the bytes decode correctly and the content was never meant to be plain text.

Use Base85 Decode now

Open Base85 Decode in the app

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