thatencode

Thatencode is a term used in computing culture to describe a family of data encoding schemes for turning arbitrary binary data into ASCII text. It is not a formal standard; rather it denotes a class of implementations that share the goals of reversibility, configurability, and safe transmission over text channels. In typical thatencode schemes, an alphabet drawn from the printable ASCII range is chosen, and input bytes are transformed by a deterministic bijection to produce a readable string that can later be decoded back to the original data.

Variants of thatencode often differ in block size, alphabet, and the presence of metadata. A common pattern is to process data in fixed-size blocks, apply a simple bijective transformation to map blocks to characters, and optionally prepend a version marker or append a checksum for integrity. Decoding applies the inverse transformation and, if present, validates the checksum. Some implementations prioritize compactness, others prioritize human readability or error detection.

Thatencode is frequently used in puzzle hunts, programming exercises, and data preparation for text-based protocols. It offers a lightweight alternative to more rigid encodings while remaining easy to implement in short programs. However, because there is no universal specification, different thatencode variants may be incompatible with one another, and users should rely on accompanying documentation to interpret the exact alphabet and block rules.

Origins of the term are informal, rooted in online programming communities in the 2010s and later. As a concept, thatencode serves as a teaching and hobbyist tool rather than an industry standard.