Compare Two PDF Files Free

Compare two PDFs free side-by-side — highlight every text difference instantly with no Adobe Acrobat needed. Mac and Windows.

100% Private
Everything runs in your browser. No files are uploaded to any server.
Side-by-Side View
See both documents together with differences highlighted.
Instant Results
Text extracted locally and compared word-by-word when you click Compare.
Precise Text Diff
Word-level differences highlighted so no edit goes unnoticed.
Read the Full Guide
AFFLIGO Compare vs Adobe & Draftable
AFFLIGO
  • ✓Word-level diff, side-by-side panes
  • ✓Change navigation + JSON report
  • ✓Scanned pages shown blank, never faked
  • ✓In-browser, free, no signup
Adobe
  • ✗Compare engine needs Pro
  • ✗Report export needs paid plan
  • ✗Scanned PDFs need Pro OCR
  • ✗Subscription for full toolkit
Draftable
  • ✗Word-diff capped free
  • ✗Full reports need paid plan
  • ✗Scanned files need OCR plan
  • ✗Power filters need Pro

When to Use This Tool

Version Comparison
Compare two versions of a contract or proposal with this PDF comparator to see what changed between drafts.
Error Detection
Find differences between original and modified PDFs to catch unauthorized changes.
Legal Review
Compare legal documents to identify added, removed, or modified clauses — a quick redline review.
Quality Assurance
Verify that edits were applied correctly by comparing before and after versions.

How to Compare PDF Files

1. Upload PDFs
Select or drag two PDF files you want to compare.
2. Compare
This online PDF difference checker instantly compares both documents side by side.
3. View Differences
See highlighted differences and download the report.

Tested by the builder: I compared two 12-page contract drafts — the word-level diff flagged 23 changed words across 5 pages in seconds, and the Change navigation jumped straight to each one without scrolling. Swapping the files reversed the green/red sides exactly as expected. Scanned pages honestly showed no text content rather than being silently skipped. All processing stayed in the browser.

Frequently Asked Questions

Yes. All processing happens in your browser. Your PDFs are never uploaded to any server.
This PDF difference checker will highlight differences side-by-side, word by word, with colors: additions in green and deletions in red with strikethrough. A stats bar shows totals for additions, removals, and unchanged words.
Yes. The tool compares text across all pages — extra pages in the longer file are compared against a blank page, so added or removed content still shows as differences.
Yes. You can download a JSON report with aggregate statistics including timestamps, filenames, page counts, and total word changes.
Scanned pages have no text layer, so they show as pages with no text content — never silently reported as identical. To check wording, run scans through our OCR PDF tool first, then compare the searchable files.
Yes. The Change navigation buttons with a live counter step directly from one word-level difference to the next, and per-page view lets you inspect each page's changes in isolation — no manual scrolling through dozens of pages.
Yes, one tap on the swap button exchanges base and compared files — additions become removals and vice versa. Useful when you loaded the drafts in the wrong order; no re-upload needed. Files up to 1GB each are accepted, though very large files depend on your device memory since everything runs in your browser.
Enter the password when prompted — the tool unlocks the file in your browser and extracts its text for comparison. The password never leaves your device.