- Drag it in, choose it, or paste it. It is read here in the tab and never uploaded.
- The settings column holds 2 controls for this tool. The defaults suit most files.
- “Compare” works on your device, then Original and Result sit side by side with a download.
About Compare PDF
Compare PDF finds what changed between two versions of a document, either word by word or by overlaying the drawn pages, and writes the result as a comparison report.
Two versions go in two slots: A is the earlier one, B the later one, and that order decides which changes read as additions and which as deletions. Get them the wrong way round and the report is still correct, just inverted.
Word by word pulls the text out of both documents, aligns it, and lists what was inserted, deleted and changed, with the page each change sits on. It is the mode for a contract or a report — anywhere the wording is the thing that matters — and it works even when the two versions paginate differently.
Page against page draws both documents and overlays them, so anything that moved shows up as a shadow. It is the mode for a layout, a drawing or a form, where a shifted line or a resized logo is exactly what you are looking for and no amount of text comparison would find it.
Either way you get a comparison report as a PDF, alongside the full comparison on screen.