Compare PDF
Upload two PDFs and review visual page differences side by side
Compare PDF — spot what changed between two versions
Compare PDF loads two documents, checks each shared page for visual differences, and shows them side by side so you can browse mismatched pages. Use it for contract revisions, proof cycles, or “did this export change?” checks — free on pdfLaunch.
Need one combined file instead? Use Merge PDF. Rewriting text in a single file? That is Edit PDF. Hiding secrets before sharing? Use Redact PDF.
What this comparison actually checks
Page counts first
You see how many pages each PDF has. Extra pages on either side count toward the difference total.
Visual page raster check
Shared pages are rendered and compared pixel-wise. Layout shifts, text swaps, and image changes that alter the page image are flagged.
Side-by-side inspection
Browse page by page with Previous/Next. Differing pages are marked in the page indicator so you jump straight to changes.
Honest limits
This is a visual compare, not a Word-style tracked-changes or clause redline report. Tiny anti-alias differences below the threshold may not flag.
How to compare two PDFs here
Upload PDF 1 and PDF 2
Each file can be up to 25 MB. Drop them on the two slots (order = left/right preview).
Wait for the page scan
The tool walks shared pages and tallies how many look different, plus any page-count mismatch.
Browse the previews
Use Previous/Next to inspect pages side by side. Differing pages are called out in the indicator.
When people compare PDFs
Identical page counts with zero flagged pages means the renders matched within the visual threshold — still spot-check critical pages when the stakes are high.
Compare vs merge, edit, and redact
Comparison stays in your browser
Both PDFs are rendered locally with pdf.js — we do not upload them for a server-side diff
- Local render: page images and pixel checks run on your device.
- No compare upload: unlike OCR or Office converters, Compare does not send the files for server processing.
- Two slots only: pair exactly two PDFs (25 MB each) for a focused side-by-side review.
- No account wall: compare without registering.
Compare PDF FAQ
How does pdfLaunch decide that a page differs?
Each shared page is rendered and compared visually. If enough pixels differ (or the page sizes differ), that page is counted.
Can I browse pages after the scan?
Yes. Use Previous/Next to view PDF 1 and PDF 2 side by side. Differing pages are marked in the indicator.
What if the two PDFs have different page counts?
Shared pages are compared; extra pages on either side are counted as differences.
Is this a legal redline / tracked-changes report?
No. It is a visual page compare, not a clause-level legal redline or Word revision report.
Do identical scans always show zero differences?
Near-identical renders should. Re-encoded exports with small anti-alias noise may occasionally flag; always spot-check critical pages.
How large can each PDF be?
Up to 25 MB per file.
Are my files uploaded when I compare PDFs?
No. Rendering and comparison run in your browser.
Can I compare more than two PDFs at once?
Not in one pass — upload a pair, review, then compare another pair.
Does Compare merge or edit the files?
No. It only analyzes and previews. Use Merge or Edit if you need to change files.
Do I need a pdfLaunch account to compare PDFs?
No. Upload both files and review differences without registering.