freeformat

Freeformat, or free format, is a term used in computing to describe data, input, or source code that is not bound to a fixed structure or fixed field positions. In data storage and interchange, free-format data relies on separators such as whitespace or punctuation to divide fields, rather than occupying fixed character columns. This makes records easier to adapt to varying amounts of information and to human editing, but it requires explicit parsing rules and escaping for embedded separators.

Common examples include delimited text formats such as CSV and other whitespace- or punctuation-delimited records, as well as plain log messages that append human-readable fields. Real-world free-format data often includes quoting or escaping rules to retain literal separators and to preserve data integrity.

In programming, free-format can refer to source code layout rules that do not depend on column-based structure. Fortran 90 introduced free-format source form, allowing tokens to appear in any column with flexible line structure, in contrast to legacy fixed-format sources. Other languages tolerate free-format style to varying extents, and many emphasize readability through consistent indentation and line breaks.

Advantages of freeformat include greater flexibility and ease of editing, especially when field counts vary. Drawbacks include parsing complexity, potential ambiguity without careful conventions, and sometimes less efficient storage or processing due to the need for escaping and tokenization.

See also fixed-width formats, CSV, and JSON.