Document Delta vs SmarterDiff

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.

SmarterDiff is a free browser-based tool for comparing text, Word documents, PDFs, spreadsheets, folders, and images. Text comparisons can show line, word, or character differences, with options to ignore case and whitespace. Excel and CSV comparisons check cell values and formulas, while image comparisons use pixel differences with overlay, side-by-side, and slider views. It can compare finalized.docx text, but not Word tracked-change markup; scanned PDFs without embedded text cannot be compared as text. SmarterDiff says comparisons run in the browser and files or results are not sent to its servers or external services. Comparisons can work offline after the first page load while browser libraries remain cached. File size depends on available computer memory and browser limits. It is a manual, one-off tool without workflow automation or integrations. The Free plan costs nothing, is ad-supported, requires no account, and has no artificial limits. Google AdSense may set ad-targeting cookies.