Compare PDF

Compare two versions of a PDF to see changed, added and removed text side by side, or spot visual changes page by page. Runs in your browser.

Reviewed by Dany, RightSums team · Updated

Runs in your browser. Your files are not uploaded.

pdf-view · PDF tool · UK & US

Load the original as PDF A and the revised file as PDF B. Text comparison reads the lines of both documents, lines them up and marks each as changed, removed, added or unchanged, with the exact words highlighted inside changed lines and a page number beside each side. Tick Only show changes to fold unchanged runs down to two lines of context. Visual comparison draws the same page from both files at the same scale and paints differing pixels red over a faded copy of A, with the share of the page that differs. Scan all pages lists every page with visible changes. You can export a PDF report that lists up to 3,000 changes. Scanned files have no text, so use the visual mode or PDF OCR.

Accepted inputs

  • PDF (original)
  • PDF (revised)

Outputs

  • On-screen comparison
  • PDF difference report

How to use the Compare PDF

  1. Add the original document as PDF A and the new version as PDF B.
  2. Read the text comparison, which shows changed, removed and added lines with the edited words highlighted.
  3. Switch to Visual comparison to see pixel changes in red, and click Scan all pages to list affected pages.
  4. Click Export diff report to download a PDF summary of the differences.

Frequently asked questions

Does it compare formatting or only text?

Both, in separate modes. Text comparison finds wording changes but ignores font, colour and layout. Visual comparison renders each page and marks every area where the pixels differ, so it catches moved images, new logos and formatting changes that the text view misses.

Can I compare scanned PDFs?

Yes, with the visual comparison, which works on page images. The text comparison needs a text layer, so for scans it will tell you there is no selectable text. Run PDF OCR on both files first if you want a word-level comparison.

Why does the visual comparison flag every page after an insertion?

Visual comparison matches pages by number, so page 5 of A is compared with page 5 of B. If a page was added or removed, every later page is out of step. Use the text comparison in that case, as it lines up matching lines wherever they fall.

Can I download a comparison report?

Yes. Export diff report creates a PDF with the file names, counts of changed, removed and added lines, and each change with its page numbers, up to 3,000 changes. If you ran Scan all pages, it also lists the pages with visual differences.

Are my documents uploaded when I compare them?

No. Both PDFs are read and compared by code running in your browser, so contracts and drafts never leave your device. The report is also built locally and downloaded straight to your computer.

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