Compare PDF

Use this tool directly in your browser with local WebAssembly processing - your files stay on your device unless you explicitly choose an AI feature that sends extracted text to our API. JoyPDF offers a free tier for core PDF tasks and an optional Premium plan for advanced limits and AI-powered workflows.

Guide & FAQ

Compare PDF

Overlay revisions and highlight differences instantly.

About this tool

Spot textual differences between two PDF versions - contract v3 vs v4, spec revision A vs B - with a line-by-line diff report generated locally in your browser. Upload both files, run compare, download a text report showing removed and added lines. Free, no account. JoyPDF compares extracted text, not pixel overlay - formatting-only changes may not appear if text strings match; scanned PDFs need OCR first for meaningful diff.

What you get

Output: plain text diff report - not highlighted overlay PDF.
Method: extracted text line comparison - fast for contract word changes.
Limits: layout-only changes invisible if text unchanged; images not compared pixel-wise.
Scans: need OCR PDF text layer or diff is empty/minimal.
Order: file A vs file B - minus lines from first, plus from second typically.
Match message: 'Documents match' when no textual line differences detected.

When to use

Lawyer reviewing whether counterparty PDF changed clause language from yesterday's draft.
Engineering checking if published spec PDF text matches approved revision.
Compliance verifying policy PDF text against prior year version.
Quick sanity check before signing that attached PDF matches emailed draft.

Why JoyPDF for this

Compare services upload both contract versions to cloud diff engines - exposing unrevised deal terms. JoyPDF diffs locally: two PDFs never leave browser during text extract and compare - suitable for confidential M&A drafts.

How to use

1Add two PDFsSelect original and revised file - both load locally, nothing uploads to comparison servers.
2Extract textJoyPDF pulls text from each PDF on your device - OCR layer used if present on scans.
3Generate diffLine-by-line comparison marks removals with minus and additions with plus - like code diff.
4Download reportSave .txt diff report for reviewers or paste into issue tracker - not a merged visual PDF.

100% in-browser

Files stay on device

GDPR-friendly

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Common questions

Does Compare PDF show visual side-by-side highlights?

JoyPDF outputs textual diff report (.txt), not colour overlay on PDF pages - like git diff for extracted lines. Visual pixel compare needs specialised graphics tools. Text diff excels at clause wording changes; fails on moved logo without text change. For word-level contract review, text diff is often faster than printing both versions.

Why does compare say documents match when I see layout differences?

Extracted text lines identical - only fonts, spacing, or images moved. Compare PDF won't flag purely visual redesign. Use manual review for marketing PDFs. Add OCR to scans so text enters diff; otherwise scans compare as empty.

Can I compare scanned PDF contracts?

Run OCR PDF on both scans first to add consistent text layers - then compare. OCR errors may cause false diffs on smudged characters. Born-digital PDFs compare best. For signed scan vs unsigned scan, expect many diffs from signature block alone.

Are both PDFs uploaded to compare?

No. Text extraction and diff run entirely in browser. Two confidential versions stay local - diff report downloads to your machine only.

Compare PDF vs redline in Word track changes?

Word track changes shows author edits in DOCX workflow - Compare PDF works on fixed PDF exports when Word unavailable. Convert to Word only if you need inline track changes UI; compare PDF for quick PDF-only pipeline.

Which file should be 'first' when comparing?

Convention: first file is baseline - diff shows minus lines removed from first relative to second and plus additions from second. Swap file order if diff reads backwards mentally. Label files clearly when archiving report.