When to compare PDFs
The most common scenarios: a client returned a "signed" contract and you want to verify nothing was quietly changed, you're reviewing two versions of a report and need to identify what was updated between drafts, a colleague sent a revised document and you want to see exactly what changed without reading the entire thing again, or you need to confirm a legal document matches the version that was approved before signing.
How to compare two PDFs free — step by step
- Open ihatepdf.cv/compare-pdfs — no sign-up required
- Upload the first PDF (original version) on the left panel
- Upload the second PDF (revised version) on the right panel
- Both documents display side by side with synchronized scrolling
- Scroll through both simultaneously to visually identify differences page by page
What to look for when comparing contract PDFs
- Text changes — words added, removed, or reworded in clauses
- Number changes — pricing, dates, quantities, penalty amounts, interest rates
- Layout changes — sections moved, pages added, or clause numbering shifted
- Signature presence — confirm signatures appear on the correct fields
- Subtle formatting — font changes, spacing adjustments that might indicate paragraph deletions
After comparing — edit the discrepancies
If you find unauthorized changes, use Edit PDF Text to correct the revised document back to the agreed terms. If certain sections need to be removed before redistribution, use Redact PDF to permanently destroy the sensitive content.
How to catch changes an automated diff would miss
Side-by-side review with synced scrolling actually outperforms automated PDF diffing for the changes that matter most in contracts and agreements. Automated tools flag every reflowed line as a "difference" and drown you in noise, while quietly missing a single swapped digit in a price or date. Work methodically: zoom both panels to the same level, read numbers character by character (1 vs 7, 3 vs 8, decimal places, currency symbols), watch for clause numbers that jump, and check whether a paragraph's line count changed — a shorter block often means a sentence was deleted. For a forensic check, extract the text from both versions and paste them into any text-diff tool to confirm word-for-word.
Comparing scanned or image-based PDFs
If one or both files are scans, there is no text layer to read, so compare them visually here and run each through OCR first if you also want a selectable-text version. OCR makes it possible to extract and diff the recognised text, which is the fastest way to confirm that a re-scanned, re-signed contract matches the copy you approved.
Frequently asked questions
Can I compare a scanned PDF?
Yes — view both scans side by side here. To compare them at the text level, run each scan through OCR first so the words become selectable and extractable.
How do I compare two PDFs on my phone?
The tool works in mobile browsers, but a side-by-side layout is far easier to read on a tablet or laptop. On a phone, compare in portrait one page at a time, or rotate to landscape for more width.
Does the comparison tool automatically highlight differences?
The tool provides synchronized side-by-side viewing — scroll both documents together to spot differences page by page. This visual approach reliably catches even subtle layout and formatting changes that automated diffing can sometimes miss.
Are my documents uploaded to a server?
No. Both PDFs are rendered entirely in your browser. Nothing is uploaded anywhere.
Is there a page limit?
No. Compare PDFs of any length — the tool loads and renders both simultaneously.