About ASCII85 Encoder

Adobe ASCII85 (base85) for compact binary in PDF/PostScript payloads. Part of the DevTools Surf developer suite. Browse more tools in the Encoding collection.

Use Cases

• PDF developers encoding binary streams inside document files
• PostScript programmers embedding images in print jobs
• Data engineers choosing compact encoding for binary payloads
• Developers comparing encoding efficiency versus base64

Tips

• ASCII85 is 20% more compact than base64 encoding
• Used natively in PDF and PostScript file formats
• Wrap output in <~ and ~> delimiters for Adobe compatibility

Fun Facts

• ASCII85 was developed by Paul Rutter for the btoa utility in 1984, encoding every 4 bytes of binary data into 5 ASCII characters — an 80% efficiency ratio.
• Adobe adopted ASCII85 (renaming it Ascii85) for PostScript and PDF, where binary data must be transmitted through 7-bit-clean channels.
• The 'z' shortcut in ASCII85 represents four zero bytes as a single character — a simple but effective compression for data with many null sequences.

FAQ

What's ASCII85?

An encoding that uses 85 printable ASCII characters (vs base64's 64). Encodes 4 bytes in 5 chars — 5% less overhead than base64.

Where is it used?

PDF and PostScript primarily. Not common for general-purpose data transport (base64 has won that space).

Adobe variant or standard?

Adobe ASCII85. Includes the <~ and ~> delimiters. For Zeromq's Z85 variant (different character set for strict safety) use a different tool.

Is it URL-safe?

No — ASCII85 uses characters like ~ and < that need URL-encoding. For URL use, base64url is the right choice.