Free online semantic diff checker. AI-powered analysis + standard diff to pinpoint substantive changes and filter out mere rephrasing. Perfect for writers and developers.

🚀 Introducing WhatDiff Hello world! Ever struggled to sort out real content changes from minor rephrasings when comparing two document versions? WhatDiff not only gives you the usual line-by-line diff, but uses AI-powered semantic analysis to: Highlight overlapping concepts and net new ideas Classify edits as simple rephrasing, structural rearrangement, or genuinely new content Score similarity across conceptual themes, factual claims, and document structure Summarize the most substantive changes in plain English Whether it’s code reviews, copy editing, legal contracts, or any situation where you need to zero in on what really changed, WhatDiff cuts through the noise so you can focus on the updates that matter. 👉 Try it now at whatdiff.com and see the difference for yourself!