Upload two versions of a PDF and see exactly what changed — added lines in green, removed lines in red, page by page.
The "before" version
The "after" version
Note: Works with digital PDFs only — scanned PDFs with no text layer cannot be diffed.
No. The tool needs selectable text embedded in the PDF. Scanned PDFs have no text layer so no diff can be produced.
PDF.js extracts individual text items. The tool groups items that share the same Y coordinate into logical lines, then diffs those lines — giving a word-processor-style view.
Pages only in the revised PDF are marked "New page" (green border). Pages only in the original are "Removed page" (red border).
Both documents are compared entirely inside your browser — no files are uploaded and no text is sent to any external service. This is important when comparing confidential contracts, legal amendments, or internal policy documents where the content must not leave your device during the comparison process.
No account is required. The comparison engine, diff highlighting, and page navigator are all available without sign-up. Compare a two-page amendment or a 200-page policy document with the same tool and the same privacy guarantee — there is no page limit.
The comparison tool works on any device with a modern browser. Compare two versions of a contract on your phone while reviewing a draft, or run a quick audit of a regulatory document update on your laptop. The side-by-side diff view adapts to any screen size.
The tool compares extracted text content line by line — additions, deletions, and modified lines are all highlighted. It does not detect changes to images, formatting, fonts, colours, or layout. Only textual content differences appear in the results. For visual or design-level changes between PDF versions, a side-by-side visual review is still needed.
The comparison requires a text layer in both PDFs. Scanned documents without OCR contain no selectable text and the tool will show no differences even if the visual content differs. Use the OCR PDF tool to add a text layer to each scanned document before running the comparison.
Yes — the tool compares page by page up to the length of the longer document. Pages that exist in one document but not the other show all their lines as added (if new) or deleted (if removed). If the document structure changed significantly between versions — pages inserted or removed in the middle — the per-page comparison may show large blocks of changes that are positional rather than content-based.
Lines that appear visually identical may differ in whitespace, Unicode character variants, soft hyphens, ligatures, or invisible formatting codes embedded in the PDF text layer. These micro-differences are detected by the text extraction layer even when the rendered output looks the same on screen. This is a property of the PDF format rather than a tool limitation.