Compare Two PDFs for Differences

Yes, completely free. Our Compare PDF tool has no hidden costs, no watermarks, and no registration requirement. You can process as many files as you need, each up to 100MB, at no charge. We believe professional PDF tools should be accessible to everyone — students, freelancers, and businesses alike.

Your files are fully protected. All uploads and downloads use 256-bit SSL/TLS encryption during transfer. Processing happens on our isolated Hetzner server infrastructure in Germany — your file is never shared, analysed for commercial purposes, or stored longer than necessary. Every uploaded and processed file is automatically and permanently deleted within 24 hours of processing.

Supported file types: This tool accepts PDF files up to 100MB each. If your file is larger, reduce it before uploading — for PDFs you can try our Compress PDF tool, which accepts files up to 100MB.

Yes — works on any device. The interface is fully responsive and tested on desktop, tablet, and mobile. Touch-friendly upload areas, drag-and-drop support on desktop, and mobile-optimised buttons mean you get the same experience whether you are on a MacBook, an iPad, or an Android phone. No app download is ever required — open your browser and go.

The comparison detects text additions and text deletions. The output is a marked-up text-difference report with additions shown in green and deletions in red. Note that it compares text, not visual appearance — font changes, image swaps and layout shifts are not flagged. The tool compares page by page in sequence, so it does not handle documents where entire pages have been reordered between versions.

A contract that has come back from the other side described only as "a few small changes". Feed in the version you sent and the version you received, and the differences are marked up for you rather than found by reading both documents in parallel. It is the same job for a specification that has been revised, or a policy where you need to know precisely what moved between two dated releases. The value is in catching the change nobody mentioned.

Something early in the document shifted everything after it. Insert a sentence on page two and every subsequent line moves down the page, so a comparison that works positionally sees a document in which almost nothing is where it was. Read the report from the first genuine difference and treat the cascade behind it as one change rather than hundreds. If the two files came from different sources — one exported, one printed and rescanned — the mismatch can also be down to fonts and spacing rather than words.

Poorly, because the comparison walks both documents in sequence and expects page three to correspond to page three. Reorder a document and every pairing after the move is wrong, producing a report that is technically accurate and practically useless. Put the pages back into a matching order first with Organize PDF, then compare. If one version is a scan, there is no text in it to compare at all until you run OCR PDF over it.

No. Both are read only, and neither is written back to — what you receive is a separate report showing where they diverge, leaving your evidence copies exactly as they were. That matters when the two versions are the record of a negotiation and their integrity is the point. Treat the report as a reading aid rather than as the authoritative document: it tells you where to look, and the decision about whether a change is acceptable stays with the person reading it.