Document Compare: Word-Level Diff for DOCX and Text

What does document compare do?

Document compare shows what changed between two versions of the same document: words that were deleted are struck through in red, words that were inserted are underlined in green, and everything else reads as normal text. It works paragraph by paragraph and then word by word inside each changed paragraph, so a one-word edit in a long paragraph shows up as one word, not as the whole paragraph rewritten.

You can paste text or open files. Word documents (.docx) are unpacked and read in your browser; plain text, Markdown, HTML, CSV and JSON files are read as text. Nothing is uploaded to a server.

When to use it instead of a text diff

Use document compare for prose: contracts, policies, README files, specs, blog drafts, release notes and anything someone edited without track changes switched on. Line-based diff tools are built for code, where each line is a unit; in prose a paragraph is one long line, so a line diff marks the entire paragraph as changed and leaves you hunting for the edit.

For code, configs and data files, the Text Diff Checker is the better fit, because it keeps line numbers from both versions.

Example

A vendor sends back your services agreement as a .docx with no tracked changes. Open your original on the left and their version on the right and press Compare. The result shows "within thirty (30) days" with "thirty (30)" struck through and "sixty (60)" inserted, and a new sentence added to the liability clause highlighted in green. The summary bar counts words added and removed and how many paragraphs changed, so you know whether you are looking at three edits or thirty before you start reading.