The PDF-only negotiation
Counterparties send PDFs for good reasons: they do not want their metadata, comments or tracked-change history leaving the building. The cost lands on the receiving side, which now has to work out what changed between the draft it sent and the PDF it got back, with no tracked changes to rely on.
The cover email says "minor changes to clause 8". It rarely says anything about the changed notice period in clause 14 or the extra sentence in the limitation of liability.
What a contract redline needs to show
- Every inserted, deleted and reworded clause, at word level, not paragraph level.
- Changed numbers, dates and cross-references inside otherwise unchanged sentences.
- Paragraphs that moved rather than changed, reported as moves so they do not swamp the list.
- The page in both versions where each change appears, so a reviewer can go straight to it.
- Formatting changes separated from text changes. Bold added to a defined term is worth knowing about; it is not the same as a changed obligation.
Three workflows that come up every week
Redlining the returned draft. Upload your last draft as the older version and the counterparty's PDF as the newer one. Work down the change list. Anything not mentioned in the cover email is the first thing to raise.
Verifying the execution copy. Before signature, compare the execution PDF against the final agreed draft. The expected result is zero substantive changes. Anything else stops the signing.
Checking an amendment. Compare the amended and restated agreement against the original. The change list should contain only the sections the amendment was meant to touch.
Scanned signature copies
A signed copy that was printed, signed and scanned has no text layer unless it went through OCR. If your DMS applies OCR on ingest, the comparison works; formatting differences are ranked low because OCR guesses bold and italic from glyph shapes. If there is no OCR layer, the comparison cannot see text and will say so.
Doing this at volume
A firm that reviews dozens of returned drafts a week does not want a browser tab per document. The engine behind the web tool is also a REST API that a DMS or contract lifecycle system can call on every new version, storing the change list and the redlined PDF against the matter. Enterprise deployments can run inside the firm's own network.
Try it on your own documents. Upload two versions on the homepage. Documents up to 30 pages need no account, and nothing is stored.
Industry page: PDF comparison for law firms and legal teams