PDF readers and tools

The Portable Document Format, or PDF, is a file format designed to present documents the same way on any device, independent of the software, hardware or operating system used to view them. Created by Adobe and later published as an open standard, a PDF stores the exact layout of a page, including its text, fonts, images and vector graphics, so that what one person sees matches what another sees and what will print. This fidelity made PDF the common choice for forms, manuals, scanned documents and anything intended to look fixed.

The most basic tool is the reader, or viewer, which displays a PDF and allows pages to be scrolled, searched and printed; many readers are free, and modern web browsers can open PDFs directly. Creators work in the other direction, producing a PDF from another program, often by installing a virtual printer so that any application's print output is saved as a PDF file rather than sent to paper. This makes it easy to turn documents from word processors, spreadsheets and other software into a fixed, shareable form.

Beyond viewing and creating, a range of editing and conversion tools manage existing files. They can merge several PDFs into one, split a large file, rotate or delete pages, add comments, fill in forms and reduce file size. Conversion tools extract the contents of a PDF into editable formats or, conversely, build PDFs from images and other documents. Related utilities recover or repair damaged files and rename batches of documents. A great deal of this software is available as freeware.

Frequently asked questions

Why is PDF used so widely?

A PDF preserves the exact layout of a document across different devices and software, so it looks and prints the same for everyone, which suits forms, manuals and final documents.

How is a PDF created from another program?

Often through a virtual printer: instead of printing to paper, the program's output is saved as a PDF file, so any application that can print can produce one.

Can a PDF be edited after it is made?

Yes. Editing tools can rearrange, add or remove pages, annotate, fill forms and compress files, though heavily formatted text can be harder to alter than in its original program.