About the Ascii85 and Uuencode Converter
Some older formats still turn up in PDFs, email and Usenet archives, and this tool reads and writes three of them. Ascii85 (also called Base85) packs four bytes into five printable characters and is used inside PDF and PostScript files. Uuencode wraps binary data in 'begin' and 'end' lines, as found in old mail and news posts. Quoted-Printable keeps mostly-ASCII text readable in email, writing only unusual characters as =XX. Type text or hex bytes to encode, or paste encoded text to decode. Everything is converted in your browser.
Updated September 2026
How to use the Ascii85 and Uuencode Converter
- 1Pick Ascii85, Uuencode or Quoted-Printable.
- 2Choose Encode or Decode.
- 3Type or paste your input. The result appears as you type.
- 4For binary data, tick 'Input is hex bytes' when encoding, or use Download bytes after decoding.
- 5Press Copy result, or Decode it back to check a round trip.
Three ways to put bytes into text
Computers often have to send arbitrary bytes through channels that were built for plain text, such as early email, news groups or PDF syntax. Each encoding here solves that in a slightly different way, and each has a small overhead. Knowing which one you are looking at makes decoding much easier.
- Ascii85: dense and compact, used in PDF and PostScript streams. Recognise it by the <~ and ~> markers and a mix of punctuation and letters.
- Uuencode: line oriented, every line starts with a length character. The first line reads begin, then a file mode and a name.
- Quoted-Printable: mostly readable text with =XX codes and lines ending in a single =.
Decoding tips
Copy the whole block, including the first and last lines. For Ascii85, extra spaces and line breaks are ignored, so text wrapped by an email program still decodes. For Uuencode, damaged lines are reported with their line number, which helps when a mail client changed trailing spaces. Quoted-Printable input that has a stray equals sign followed by anything other than two hex digits is rejected, because guessing could corrupt the data.
If a decode works but the result looks like random symbols, the data probably isn't text. Use the hex view or download the bytes and open them in the right program, for example an image viewer.
Encoding tips
Text is turned into bytes with UTF-8 before encoding, which is what most modern software expects. If you need exact bytes, such as a binary header, tick the hex option and enter them as pairs like 89 50 4E 47. Ascii85 has a special letter z for four zero bytes in a row, which this tool uses just as PDF writers do. The Uuencode header uses mode 644 and the file name you give; change the name if the receiver will save the file under it.
Privacy and devices
Conversions happen on your device, so pasted text and hex are not sent anywhere. The page works the same on a phone or a computer, and nothing needs installing. For everyday Base64 work, see the Base64 Encoder and Decoder, and for one-way fingerprints use the Hash Generator. For everyday text encoding, the Base64 Encoder & Decoder is more common, and the URL Encoder & Decoder is the one for web addresses.
Features
- Ascii85 with the optional <~ and ~> markers and the short 'z' form for four zero bytes
- Uuencode with a file name in the begin line, and Uudecode that reads the name back
- Quoted-Printable with soft line breaks at 76 characters and UTF-8 handling
- Hex input for encoding binary bytes, and hex display when decoded bytes are not text
- Download the decoded bytes as a file
- Specific error messages that point to the wrong character or line
Frequently asked questions
What is Ascii85 (Base85)?
Ascii85 is an encoding that represents binary data with printable characters from ! to u. Every four bytes become five characters, so the output is about 25 percent larger than the input, compared with 33 percent for Base64. PDF and PostScript use it for embedded streams.
Is this the same as Z85 or the Base85 used by Git?
No. Those are different alphabets that share the same idea. This tool uses the original Ascii85 alphabet, including the Adobe <~ ~> markers and the z shortcut. Text in another Base85 variant will give a decoding error or different bytes.
What does Uuencode look like?
A file starts with a line such as 'begin 644 notes.txt', followed by lines that begin with a length character and then the data, and ends with a line holding a backtick and the word 'end'. Uudecode turns those lines back into the original bytes.
When is Quoted-Printable used?
Email uses it for text that is mostly ASCII with a few accented letters. Letters and digits stay as they are, and every other byte becomes an equals sign and two hex digits, so é (two bytes in UTF-8) is written =C3=A9. Long lines are cut with an equals sign at the end.
Why are decoded bytes shown as hex?
Text fields can only show text. If the decoded bytes are not valid UTF-8, such as an image or a compressed file, the tool shows them as hex and lets you download them as a file instead.
Is encoding the same as encrypting?
No. Anyone can decode these formats, because there is no key. They exist to carry data through systems that only accept text. To protect a message, encrypt it first with a password.