Compare PDF
Find differences between two PDF versions — runs entirely in your browser.
Drop two PDF files here
or click to choose files — PDF A and PDF B
Find differences between two PDF versions — runs entirely in your browser.
Did someone send back a contract with changes? Need to check whether a document was altered after signing? Comparing two versions of a report or specification? PDFree lets you drop both PDFs and see every difference highlighted — no upload, no account, no Adobe Acrobat required.
Whether you need to redline a contract, verify two PDFs are identical, check a scanned copy against the original, find unauthorized changes, or proof-check a print-ready file — the diff view shows every changed area in seconds, 100% private.
A counterparty returned a signed PDF. Before relying on it, compare it against the version you sent. Any added clause, changed number, or removed paragraph shows up immediately in the diff view.
Drop the draft you sent and the marked-up version that came back. PDFree highlights every revision in red so you can review the redline without toggling between tabs or printed copies.
Confirm a copy or certified duplicate matches the original before archiving. If every page shows 0% changed, the files are visually identical — useful for compliance, auditing, and document management workflows.
Technical specifications, engineering drawings, policy documents — when a new version lands, compare it against the previous one to understand exactly what changed without reading both in full.
Compare the press-ready export against the design source to catch last-minute layout shifts, font substitutions, or colour changes before sending to print. The diff view catches what the eye misses.
Check that a physical scan matches the source file — useful when verifying certified copies, checking that a faxed document arrived intact, or confirming no pages were added or removed during scanning.
The original goes as PDF A, the revised version as PDF B. Both files are rendered locally in your browser — nothing is uploaded.
Each page is rendered at the same scale and compared. A % changed badge appears on each page so you immediately spot which pages were edited.
Use PDF A / PDF B / Diff buttons to switch between the original, the revision, and the highlighted overlay. Diff view shows changed areas in red; unchanged areas in greyscale.
PDF comparison frequently involves the most sensitive documents you handle: contracts, NDAs, financial reports, legal briefs, medical records. With PDFree, neither file is ever uploaded to any server. All rendering and comparison happens inside your browser tab using PDF.js. No cloud service, no third party, no server ever receives your documents.
To verify: open browser DevTools → Network tab while comparing. You will not see your PDFs being transmitted anywhere during processing.
| Feature | PDFree | Typical cloud tools |
|---|---|---|
| Files uploaded to server | No — stays in browser | Yes — sent to remote servers |
| File size limit | None | Usually capped on free tier |
| Daily usage limit | None | Often restricted |
| Registration required | Never | Often required |
| Price | Free forever | Free with limits / paid plans |
Yes. PDFree runs entirely in your browser. Neither PDF is ever uploaded — not to PDFree's servers, not to any third party. Open DevTools → Network tab while comparing and you will not see your files being transmitted anywhere.
Yes, if you know the password. PDFree prompts you to enter it when you open a protected file. Once unlocked, the comparison proceeds normally. PDFree cannot bypass or crack a password — it only opens files you are authorised to open.
Yes. Open PDFree in Safari (iPhone/iPad) or any browser on Mac — no app download or Adobe Acrobat required. Drop both PDFs, tap Compare PDFs, and scroll through the diff. Works entirely in the browser.
Yes. PDFree compares at the pixel level, so it works on scanned pages as well as digital PDFs. Any visible difference — a stamp, a handwritten note, a misaligned scan — is highlighted in the diff view.
Yes. After comparing, pages with no differences show a 0% changed badge. If all pages show 0% and the page counts match, the files are visually identical — useful for compliance verification, certified copies, and archiving workflows.
A redline is a marked-up version of a document — typically a contract or legal agreement — that shows tracked changes compared to an earlier draft. The term comes from marking changes in red ink. PDFree's diff view serves the same purpose: drop the original and the revised version, and changed areas are highlighted in red.
PDFree performs a visual comparison — it highlights any pixel that differs between the two PDFs. This covers text edits, formatting changes, added images, stamps, and layout shifts. If you need text-only diffing, use OCR PDF first to extract the text, then a text-diff tool.
Yes. PDFree compares all pages that exist in both files. Pages that only appear in one PDF are shown with an "Only in A" or "Only in B" badge so you immediately see which document has extra content.
No. PDFree displays the differences in your browser for review but does not generate a downloadable report or redline PDF. If you need to share the result, capture the relevant pages using your operating system's screenshot tool (Cmd+Shift+4 on Mac, Windows+Shift+S on Windows). You can then use Redact PDF to cover sensitive areas before sending.
Cover sensitive areas you found during comparison before sharing
Password-protect the reviewed document before sending
Lock the final version so form fields and annotations can't be edited
Extract searchable text from scanned pages found during comparison