Compare Two PDFs

See exactly what changed between two PDFs — a readable side-by-side text diff with the changed words highlighted, plus a visual layout overlay. Export the differences to CSV or Excel. All local.

Compare two PDFs free in your browser and see exactly what changed — a side-by-side text diff with changed words highlighted. Export to CSV or Excel.

About Compare Two PDFs

Compare Two PDFs is a free, browser-based diff tool that shows exactly what changed between an original (A) and a revised (B) PDF. It extracts each page's text with pdf.js and renders a side-by-side, word-level diff with added text highlighted green and removed text struck through in red, plus a "Visual (layout)" mode that renders both pages to canvas, runs a pixel overlay, and shows a drag-divider comparison slider. Use it to review contract edits, document revisions, or formatting changes, then export every difference to CSV or Excel (via SheetJS). Everything runs locally in your browser — neither PDF is ever uploaded, and there is no signup.

How to use Compare Two PDFs

  1. Drop your original PDF onto the 'Original (A)' zone and your revised PDF onto 'Changed (B)' (or click to browse). Both load locally.
  2. Stay in 'Text (side-by-side)' mode to read the diff: changed lines show word-level highlights (green = added, red strikethrough = removed), with a Changed/Added/Removed/Verdict summary on top.
  3. Use Prev/Next to step through pages — if the files have different page counts, it compares the first N pages they share.
  4. Toggle 'Show unchanged lines' off to focus only on the differences.
  5. Switch to 'Visual (layout)' mode to see a drag-the-divider A→B slider, a red difference overlay, and the percentage of pixels changed — useful for scanned pages or formatting shifts.
  6. Click 'Export CSV' or 'Export Excel' to download a side-by-side file of every change across all compared pages.

Frequently asked questions

Are my PDF files uploaded to a server?
No. Both PDFs are read, rendered, and compared entirely in your browser on your device — neither file is ever uploaded anywhere.
Is it free and do I need an account?
Yes, it's completely free with no signup, account, or watermark.
What's the difference between Text mode and Visual mode?
Text mode extracts selectable text and shows a word-level side-by-side diff with a Changed/Added/Removed count. Visual mode renders each page to an image, overlays the changed pixels in red, and gives a drag-divider before/after slider plus a percentage of pixels changed — better for layout, formatting, or scanned pages.
Can it compare scanned PDFs or pages with no selectable text?
Text mode needs selectable text, so for a scanned page it warns you that no text was found and suggests switching to Visual (layout) mode, which compares the pages as pixels instead. If only one side is scanned, it flags that side rather than reporting the whole page as changed.
What do the CSV and Excel exports contain?
The export builds a side-by-side table of every difference (Original vs Changed) across all compared pages — differences only, regardless of the on-screen 'Show unchanged' toggle — saved as pdf-comparison.csv or pdf-comparison.xlsx to open in Excel, Numbers, or Sheets.
What happens if the two PDFs have different numbers of pages?
It shows a warning and compares only the first N pages the two files have in common (the smaller page count), stepping through them with the Prev/Next buttons.

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