UTF8n

UTF8n is a term that appears in some technical discussions to denote a non-standard or informal variant of UTF-8. Unlike the Unicode Transformation Format 8-bit (UTF-8), which has a formal specification published by the Unicode Consortium, UTF8n has no single, universally recognized definition. As a result, references to UTF8n can describe different encodings in different contexts, and the exact behavior of any given UTF8n implementation may vary.

In general, UTF8n is described as UTF-8–like: it typically preserves ASCII compatibility and uses a variable-length scheme for code points beyond 0x7F. However, because it is not standardized, some sources report modifications such as stricter or looser validation rules, altered handling of invalid byte sequences, or constraints on the number of continuation bytes. Some descriptions also treat UTF8n as a teaching shorthand for exploring UTF-8’s design choices rather than a separate, deployed encoding.

Practical use: It is rarely used in modern software and is not supported as a distinct encoding by major standards. When interoperability is required, standard UTF-8 is recommended. If a document mentions UTF8n, it should be checked for a precise definition in that specific project or publication. See also UTF-8, Unicode, and byte encoding.