Reading Order

The sequence in which content is presented to assistive technology users, particularly screen reader users, when navigating a document or web page. For sighted users, the visual layout of a document (columns, sections, sidebars) implicitly suggests a reading flow, but screen readers must linearize this two-dimensional layout into a one-dimensional sequence. When the reading order does not match the logical structure of the content — for example, when OCR extracts text from a multi-column menu in left-to-right order rather than column-by-column — the result is confusing and cognitively taxing for screen reader users. Proper reading order is a fundamental requirement of document accessibility under WCAG, specified through DOM order in HTML, tag structure in PDFs, and reading order settings in authoring tools.