Compare PDFs - Find Differences

Compare two PDF files page by page. Pixel-diff sidebar badges, Next-Diff jump, and three compare modes: visual diff, side-by-side, text diff. Runs entirely in your browser.

Compare two PDFs page by page with three views: Visual Diff (3 panels with pixel-overlay), Side-by-Side (read both versions in parallel), or Text Diff (per-word added/removed highlights). The sidebar runs a pixel-diff scan upfront so every page is marked identical, changed, or only-in-one — jump straight to the differences with Next Diff. Runs entirely in your browser via PDF.js; both files stay on your device.

Privacy-first processing — secure, isolated, and auto-purged

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How to Compare PDFs

1

Upload two PDFs

Use the two-slot uploader — drop one PDF into each slot. A pixel-diff scan runs in the background to mark every page as identical, changed, only-in-1, or only-in-2.

2

Navigate the pages

The left sidebar lists every page with a colour-coded badge. Click a page to jump to it, or click Next Diff to skip straight to the next changed page.

3

Switch compare modes

Three tabs: Visual (3 panels — PDF 1, PDF 2, pixel overlay), Side-by-Side (2 panels aligned), Text Diff (per-word highlights for text-based PDFs). Pick whichever makes the changes clearest.

On this page

What Compare PDFs does

PDFGrover's Compare PDFs tool puts two PDFs side by side and shows which pages differ — and how. Use it for contract revisions, proofreading updated decks, or verifying a regenerated report matches last week's version.

When to compare two PDFs

  • Contract redlines — spot every change between a sent and a returned version.
  • Document versions — confirm what actually changed between v1 and v2.
  • Proofing — catch unintended edits before publishing.
  • Verification — check a regenerated export matches the approved one.

How to compare PDFs

  1. Upload two PDFs — one into each slot. A background scan marks every page identical, changed, only-in-1, or only-in-2.
  2. Use the sidebar — colour-coded badges per page; click to jump, or hit Next Diff to skip straight to the next change.
  3. Pick a view (below) that makes the changes clearest.

Three compare modes

  • Visual Diff — three panels: PDF 1, PDF 2, and a pixel overlay with changed regions highlighted.
  • Side-by-Side — both versions aligned so you can eyeball differences.
  • Text Diff — per-word added (green) / removed (red) highlights; best when wording matters more than exact layout.

Reading the sidebar badges

Green = identical · Orange = changed (with %) · Red = only in PDF 1 · Blue = only in PDF 2. The first 20 pages render immediately; the rest render as you scroll or click, so big documents stay responsive.

Limitations to know

  • Pages are matched by index. If one file inserts a page at position 5, every later page shows as "different" because the content shifted, not changed — a limitation shared by most PDF diff tools.
  • Text Diff needs real text. Scanned (image-only) PDFs have none — run them through OCR PDF first, or use Visual Diff for those.

Privacy and file handling

Compare PDFs runs entirely in your browser — both files are loaded, rendered, and diffed on your device. Nothing is uploaded, stored, or logged. No sign-up, no watermark.

Troubleshooting

  • Everything after one page shows changed — a page was likely inserted/removed, shifting the index alignment; check around the first big diff.
  • Text Diff is empty — the PDF is a scan with no text layer; OCR it first or use Visual Diff.
  • Large files are slow — the first 20 pages load first; the rest render on demand, so jump via the sidebar rather than scrolling all through.

Frequently Asked Questions