Compare Two PDF Files
What did the other side change in the contract? Which pages differ between two report versions? Upload both PDFs for a page-by-page, pixel-level comparison: identical pages are grayed out, differences are highlighted in red, and a per-page text report is included. Everything runs locally in your browser.
Drop files here (multiple allowed)
or choose from your device — no sign-up needed
Files are processed locally in your browser — never uploaded to any server
Full-release pricing preview: $6.9/mo or $49/yr · 30-day email notice before billing starts · nothing is charged during the beta
How it works (3 steps)
Upload both versions
Select file A (old) and file B (new) in order; different page counts are fine.
Page-by-page comparison
Matching pages are rendered onto the same canvas and compared pixel by pixel, tolerating anti-aliasing noise so only real changes are flagged.
Download the diff pack
Pages with differences produce red-highlighted diff images, bundled with a per-page report.txt in a zip.
Popular searches
- find differences between two PDFs
- contract version comparison tool
- PDF diff checker online
FAQ
Visually: matching pages are rendered to images and compared pixel by pixel, so any visible change (text, numbers, images, stamp positions) is marked in red. Honest note: this is not a semantic text diff — it cannot tell you “what sentence 2 of paragraph 3 now says”.
Try it ↑Shared pages are compared normally; extra pages count as fully different and the report says which file they belong to — nothing is silently ignored.
Try it ↑You get a clear “all N pages identical, no differences found” result with the per-page report. The comparison ran, so it counts as one use.
Try it ↑No — rendering and comparison run entirely in your browser.
Try it ↑No. Any change to a signed PDF (merging, compressing, watermarking…) invalidates the existing digital signature — that is the tamper-proof design of PDF signatures, not a limit of this site. Process first, then sign.
Try it ↑Yes — and you can verify it: the tool runs on open-source in-browser engines (pdf-lib, pdf.js, Tesseract OCR…) on your own device. Open DevTools → Network while processing and you will see no file upload requests.
Try it ↑Related tools
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Combine several PDFs into one file, in exactly the order you want — drag to reorder before merging
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Light PDF Edit (Whiteout + Text)
Fix a typo, change a date, or cover a stray mark: whiteout the original content and type replacement text in place