Base91 Variant
Base91 variants are encodings that adjust the alphabet or bit alignment of standard Base91 (91 characters, expansion about 1.231).
Purpose
They represent binary data more compactly than Base85 while keeping the entire output within printable ASCII.
Mechanism
The input bit stream is mapped onto the 91-character alphabet in variable-length bit groups, using a 13-bit lookup table for batch encoding; variants may adjust the alphabet order or letter-case policy.
Use cases
- High-density binary-to-text conversion
- Preprocessing for data compression
- Compact serialization