Document Delta vs PDiff

Document Delta compares two DOCX files and returns a document marked with Word's native tracked changes. Its web workflow is upload, compare, and download, with no signup required. The comparison covers paragraphs, tables, headers, footers, text boxes, content controls, and characters, detecting insertions, deletions, and formatting changes at run and character level. It can identify bold, italic, underline, font, and style changes even when the wording is unchanged. Reviewers can accept, reject, or comment on the revisions in Microsoft Word. The service also offers a REST API that compares two Word documents in one HTTP request without an SDK or API key, with examples for C#/.NET, Python, JavaScript, PowerShell, and Java. Files are processed in memory and discarded when comparison finishes. The free demo costs nothing. Each API file is limited to 500 KB, and the public API allows 10 requests per hour per IP address. The free comparison tool is in beta and actively improving.

PDiff is desktop software for comparing PDF documents and identifying differences in layout, formatting and page breaks. It displays PDFs side by side, synchronizes extracted text with the pages and highlights deviations in both views. Reviewers can navigate differences, mark changes accepted, hide less relevant changes and add comments. Filtering and review tools include exclusion areas, page ranges, text-flow and table tools, replacement rules, comments and OK checkmarks.

PDiff can compare PDFs with DOC/DOCX, RTF, TXT, XLS and other common formats, converting non-PDF files through their native applications. Outputs include tabular, annotated and side-by-side PDFs, XML, CSV, PDiff project files and CLI return codes. PDiff Professional adds GUI batch processing and command-line operation. CSci Computer Science GmbH describes uses including quality assurance, regulatory compliance, contract and legal review, pharmaceutical packaging and technical documents. The software supports Unicode, including Chinese, Japanese, Korean, Arabic and Hebrew. The maker says processing is local and documents are not transferred over the internet. Business customers can request a free full-functionality trial; pricing for editions is on request.