Preserving exact document layout requires using fixed-layout formats like PDF (Portable Document Format) or XPS (XML Paper Specification). These formats capture the precise arrangement of text, images, fonts, and other elements on each page exactly as intended, preventing unpredictable reflowing that happens with formats like plain text or standard HTML. They embed fonts and graphics, ensuring the document appears consistently regardless of the device or software used to view it.

The primary use case for these formats is sharing finalized documents where precise appearance is critical. Examples include legal contracts requiring identical pagination for signatures and references, or illustrated e-books/comic books where image-text placement is integral to the reading experience. Industries like legal, publishing (especially print-to-digital), and formal reporting heavily rely on PDF, while XPS is often used in Windows-centric environments and printing.

The key advantage is unmatched visual fidelity across platforms. However, fixed-layout formats are less accessible for screen readers and harder to edit or repurpose content compared to flowable formats like DOCX or EPUB. Future innovation focuses on enhancing accessibility features within PDFs (like tagged PDF) and developing hybrid standards (e.g., EPUB Fixed Layout) that combine layout preservation with richer functionality for digital books.