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PDF Diff -
Compare Two PDF Files Online

Compare two PDF files online and see every difference in seconds. Five views — rich text for changes on the rendered page, plain text for word-level edits, redline for legal review, image for pixel-level visual checks, and details for file metadata. Switch between them any time without re-uploading.

Your PDFs stay completely private: the entire comparison runs in your browser, so contracts, legal filings, and financial records never leave your device. Password-protected files are unlocked locally and cleared the moment you close the tab.

Five Ways To Compare PDF Documents

Pick the view that matches what you need to see, and switch between them freely without re-uploading — the same two PDFs flow through every mode.

Rich Text. Changes shown in place on the rendered PDF pages — removed text in red, new text in green — so you read the difference the way the document actually looks.

Plain Text. The extracted text from both PDFs side by side or unified, with differences highlighted word by word and formatting stripped away.

Redline. New wording underlined in blue and removed wording struck through in red, combined into one marked-up document — the format legal reviewers expect.

Image. Compares the pages as pictures, pixel for pixel — catching moved logos, shifted margins, font swaps, and anything text extraction would miss.

Details. A side-by-side table of each file's properties — page count, size, author, producer, dates, PDF version, and encryption — with the differences flagged.

Legal Redline Comparison For Contracts

Redline mode produces the marked-up draft lawyers and contract reviewers already know: new wording underlined in blue, removed wording struck through in red, combined into one document that reads like a tracked-changes review.

Drop in two versions of a contract, NDA, or policy and the redline is ready to share. Export it as a new PDF that opens in any reader, with no extra software needed — and because the comparison runs on your computer, confidential drafts never leave your device.

Example: NDA Section Redline
This Agreement is effective as of January 1, 2024
between Acme Corp. (the "Disclosing Party")
and the Recipient (the "Receiving Party").
The Receiving Party shall keep Confidential
Information strictly confidential for five (5)
Information strictly confidential for three (3)
years from the Effective Date.
Insertions: underlined blueDeletions: red strikethrough

What The Redline Export Includes

  • A new PDF with insertions in blue and deletions struck through in red
  • The marked-up pages exactly as shown on screen
  • Export all pages, or just the left or right document
  • Opens in any PDF reader, on any device

Text Changes And Visual Changes

A PDF can change in two different ways, and this tool covers both. Text views — rich text and plain text — pull the words out of each page and compare them, so an edited clause, a changed figure, or a reworded paragraph is highlighted precisely, down to the word. That's the right lens for contracts, reports, and anything where the wording is what matters.

The image view compares the pages as rendered pictures, pixel for pixel, with a sensitivity control and modes for side-by-side, fade, slider, flicker, highlight, and difference. It catches the changes text extraction can't see — a moved logo, a shifted margin, a swapped font, a re-exported chart — which is exactly what you need when layout and design are the point.

Password-Protected PDF Comparison

Encrypted PDFs work the same way as any other. Drop them in, type the password when prompted, and the comparison starts immediately — no need to strip the protection in another tool first.

The password stays on your device and is used only to unlock the file for comparison. Nothing is uploaded, and everything clears the moment you close the tab.

  • Detects password-protected PDFs on upload
  • Password entered and kept on your device only
  • All five comparison views work once the file is unlocked
  • Handles two files with different passwords in the same session

How To Compare Two PDF Files Online

Four steps — no sign-up, no downloads, nothing uploaded.

  1. 01Add Your Original PDF. Drag it onto the left panel or click to browse. It's parsed and rendered in the browser; if it's encrypted, you'll be asked for the password.
  2. 02Add The Changed PDF. Drop the newer version on the right. Both load together and their pages line up automatically.
  3. 03Pick A View. Switch between Rich Text, Plain Text, Redline, Image, and Details — the PDFs stay loaded as you move between them.
  4. 04Export The Result. Save the comparison as a new PDF — all pages, or just one side. The redline export is ready to hand to a reviewer.

Why Use This PDF Compare Tool

Free, private, and built for the questions people actually ask when comparing PDFs. Eight things make it stand out:

  1. 01Five Views. Rich text, plain text, redline, image, and details — text and visual comparison in one tool, switchable without re-uploading.
  2. 02In-Place Rich-Text Diff. Changes are shown in colour on the rendered pages — removed in red, added in green — so you see the difference in context, not as a separate report.
  3. 03Pixel-Level Image Diff. Compares pages as pictures with a tunable sensitivity and six sub-modes, catching moved logos, shifted margins, and font swaps text can't detect.
  4. 04Editable Redline Export. Exports a new PDF with insertions underlined in blue and deletions struck through in red — ready to send to counsel or a counterparty.
  5. 05Password Support. Encrypted PDFs are detected and unlocked locally with the password you provide, then compared normally — the password never leaves your device.
  6. 06Full Document Details. Page count, file size, author, producer, dates, PDF version, and encryption status, compared side by side with the differences flagged.
  7. 07Export As PDF. Save the rich-text, image, or redline comparison as a new PDF — all pages or just one side — to email or archive.
  8. 08100% Private & Free. PDFs never leave your device; the whole comparison runs client-side. No registration, no quota, no premium tier.

Contracts, Reports, And More

Any PDF — text-based, image-heavy, or password-protected. These are the comparisons people run most.

Legal & Contracts

Contract negotiations, NDA revisions, and regulatory filings — redline mode produces the marked-up draft legal reviewers expect, exportable as a PDF.

  • Comparing contract versions during negotiation
  • Reviewing NDA and agreement changes
  • Privacy-policy and terms-of-service updates
  • Regulatory filing revisions
  • Merger and due-diligence documents

Reports & Design

Financial reports, brochures, and design proofs — image mode catches the layout shifts a text comparison would miss.

  • Design-proof reviews between rounds
  • Layout and formatting changes
  • Brochure and flyer revisions
  • Architectural drawings
  • Quarterly financial-report comparisons

Technical & Academic

Specs, papers, and manuals — plain text pulls the wording out of the formatting so you focus on what was said.

  • Engineering change orders
  • Academic paper revisions
  • Technical-specification updates
  • User-manual comparisons between releases
  • Research-paper peer-review changes

Frequently Asked Questions

How do I compare two PDFs for changes?

Drag the original into the left panel and the changed version into the right. The pages line up automatically and every difference is highlighted — switch between rich text, plain text, redline, image, and details views at the top, with no Compare button to press.

Can I compare password-protected PDFs?

Yes. Upload the encrypted file, enter the password when prompted, and the comparison runs normally. It works even when the two files have different passwords, and the password never leaves your device.

How does redline mode work?

It combines both PDFs into one marked-up document with new wording underlined in blue and removed wording struck through in red. You can export that as a new PDF that opens in any reader.

Can I see visual differences, not just text?

Yes. The image view compares the pages as pictures, pixel for pixel, with a sensitivity control and six sub-modes — side by side, fade, slider, flicker, highlight, and difference — so moved logos, shifted margins, and font swaps all show up.

Can I compare the wording of two PDFs?

Yes. Rich text highlights changes in place on the rendered pages, and plain text strips the formatting to show exactly which words differ, side by side or unified — the right choice when the wording is what matters.

Can I save or export the comparison?

Yes. The rich-text, image, and redline comparisons export as a new PDF — all pages, or just the left or right document — ready to email or archive.

What details does it compare beyond the pages?

The Details view puts both files' metadata side by side — page count, file size, author, producer, creation and modification dates, PDF version, and encryption status — and highlights what differs.

Are my PDFs private?

Yes. Everything runs in your browser — your PDFs are never uploaded, stored, or sent to a server, and passwords stay local. That makes it safe for contracts, legal filings, and financial or medical records.

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