You can reflow a PDF document to read it on handheld devices, smaller displays, or standard monitors at large magnifications, without having to scroll horizontally to read each line.

When you reflow an Adobe PDF document, some content carries into the reflowed document and some doesn’t. In most cases, only readable text reflows into the reflowed document. Readable text includes articles, paragraphs, tables, images, and formatted lists. Text that doesn’t reflow includes forms, comments, digital signature fields, and page artifacts, such as page numbers, headers, and footers. Pages that contain both readable text and form or digital signature fields don’t reflow. Vertical text reflows horizontally.

As an author, you can optimize your PDF documents for reflow by tagging them. Tagging ensures that text blocks reflow and that content follows the appropriate sequences, so readers can follow a story that spans different pages and columns without other stories interrupting the flow. The reading order is defined by the structure tree, which you can change in the Structure pane.

Headings and columns (top) reflow in a logical reading order (bottom).