Linearization (Fast Web View)

Linearization, marketed by Adobe as Fast Web View, is a way of reorganising a PDF's internal byte order so it can be displayed before the whole file has arrived. In a normal PDF the cross-reference table that indexes every object sits at the very end, so a viewer technically needs the complete file to know where things are.

A linearized PDF restructures this. The objects needed to render the first page, plus a special hint table, are moved to the front, and the file is arranged so that a server supporting byte-range requests can stream it page by page. The reader shows page one almost immediately and fetches the rest on demand, which is why a large linearized document feels responsive over a slow connection instead of forcing you to wait for a full download.

Linearization changes only the file's layout on disk, not its visible content, so the document looks identical. It is most useful for big files served over the web. Because it is a structural rewrite of the PDF, it is the kind of transformation that a browser-based engine can perform locally as part of optimising a document.