Document Delta vs UltraCompare

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.

UltraCompare compares and merges files, folders, and documents, including Word, Excel, and PDF. It can show two or three files side by side and lets users merge differences visually. Folder tools compare, merge, and synchronize directory structures, with rule-based automation available. For spreadsheets and other tabular data, it can compare and merge cells, rows, or columns, including across multiple Excel sheets. UltraCompare works as a diff and merge tool with Git, Subversion, and CVS. It can compare remote files over FTP or SFTP and by URL, and folders over FTP and network shares. ZIP, RAR, and JAR contents can be compared without extraction. Additional tools include highlighting for characters, words, or lines; options to ignore whitespace or case; editable comparisons; saved sessions; and HTML or text reports. The maker lists Windows, macOS, and Linux, while a fully functional Windows trial includes all features for 30 days. There is no free plan. Subscriptions start at $99.95 a year for Core or $119.95 a year for Enterprise; perpetual options cost 179.95 USD or 249.95 USD once.