Ascii85
How Ascii85 works
Ascii85 (also called Base85) encodes 4 bytes of binary data into 5 ASCII characters, achieving 80% efficiency compared to Base64's 75%. Adobe developed it for PostScript and PDF, where binary streams need to survive text-only channels. The encoding uses 85 of the 95 printable ASCII characters, skipping those that cause problems in certain contexts.
A special shorthand exists: four zero bytes encode as a single "z" character instead of five characters, which compresses null-heavy data significantly. The btoa/atob variants (used in some Unix utilities) differ from Adobe's version in delimiter and whitespace handling. If you need binary-to-text encoding for web use, Base64 has broader support - Ascii85 is mainly relevant when working with PDF internals.
A special shorthand exists: four zero bytes encode as a single "z" character instead of five characters, which compresses null-heavy data significantly. The btoa/atob variants (used in some Unix utilities) differ from Adobe's version in delimiter and whitespace handling. If you need binary-to-text encoding for web use, Base64 has broader support - Ascii85 is mainly relevant when working with PDF internals.