DiffPDF 軟體目前提供 Windows 與 Mac OS X 兩種版本，使用方法相當簡單，只要先分別在兩個方框中選取你要比對的 PDF 檔，選擇看是要用文字比對方式（Text）或外觀比對模式（Appearance），按下「Compare」按鈕後，即可自動在視窗中顯示兩份 PDF 文件不同的位置。
Added new --dpi option that helps with ignoring small differences, particularly when combined with channel-tolerance. Thanks @bendablegears! Added --grayscale option to convert the diff output to grayscale and only use color for pixels with differences. T
DiffPDF is useful for anyone who needs to compare PDFs, reports, books, or labels—for example, archivists, engineers, journalists, linguists, packagers, publishers, researchers, software testers, and translators.
DiffPDF is a straightforward yet powerful free utility for Windows that enables users to efficiently identify changes and differences between PDF files.
