Compare PDF · 2 min read

How to Check If Two PDF Files Are Identical — Free

Need to verify that two PDFs are exactly the same — no changes, no tampering? Here's how to check PDF identity with pixel-level accuracy in your browser.

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Step 1 — Upload Both PDFs

Go to pdfeditor.onl/compare-pdf. Upload the first PDF as File A and the second as File B.

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Step 2 — Click Compare

Click Compare. The tool analyses every page from both files pixel by pixel. The summary shows total pages, changed pages, identical pages, and average change percentage.

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Step 3 — Read the Identity Result

If the summary shows 0 changed pages and 0% average difference, the two PDFs are visually identical. If any pages show a change percentage above 0%, there are differences.

Tip: Very small pixel differences (below 0.5%) may indicate minor rendering differences rather than actual content changes — inspect those pages in Diff view to confirm.

Check PDF Identity — Free →

Frequently Asked Questions

Can two PDFs be visually identical but have different file sizes?

Yes. PDFs can contain different metadata, embedded fonts, or creation timestamps while rendering identically. The compare tool checks visual identity, not binary file identity.

Does identical mean the files are cryptographically the same?

No — the comparison is visual. For cryptographic identity verification, use an MD5 or SHA-256 hash tool. For visual and content identity, this pixel comparison is the right approach.

Is this free?

Yes — 100% free, no account required.

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