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.
