Compare PDF Files Online

Put two versions of a PDF side by side and see every word that was added, removed or reworded, highlighted in colour. Free, no sign-up, and both documents are read privately inside your browser.

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Original

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PDF file · read on your device, never uploaded

Changed version

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PDF file · read on your device, never uploaded

Compared entirely on your device. Neither file was uploaded.

How to Compare Two PDFs for Changes

A landlord sends a “slightly updated” rental agreement. A client returns a contract with “a few small edits”. Your college posts a revised syllabus. Reading both copies line by line to spot what moved is tiring, and the one clause you miss is usually the one that matters.

This comparer pulls the text out of both PDFs and lines them up. New wording is tinted green and deleted wording red; inside an edited line the exact words or characters that differ are marked. Two arrow buttons hop between edits while a small counter keeps track of where you are.

Both files are opened on your own device. Contracts, offer letters and legal drafts never travel to some remote machine for checking, and with papers like these that peace of mind counts.

No software to install Free Works on any device

Find the Differences in Six Steps

The comparer is in the panel above. Its settings sit in the column on the left.

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1. Open the Compare PDF tool

You are already on it. It runs in a current browser on a desktop, laptop or tablet. A wide screen makes the side-by-side view much easier to read.
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2. Add the original PDF

In the box headed Original, choose the older version of the document, or drag it in. This is the copy you are checking against.
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3. Add the changed version

In the box headed Changed version, choose the newer PDF. Picked them the wrong way round? Press Swap sides in the settings column.
Before you start:
- Both files must contain real text, not just scanned pictures of pages.
- Password-protected PDFs cannot be read until the password is removed.
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4. Choose what counts as a change

Tick the options that suit the document. Hide whitespace changes is on from the start, so extra spaces from a different layout do not clutter the result.

Ignore capitalsIgnore blank linesHide unchanged linesShow line numbers
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5. Press Find the differences

The result appears above the files, with a count of additions and removals. Step through the edits with the ↑ and ↓ buttons, or read the full document with the changes marked.
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6. Save a record if you need one

Press Download .diff in the settings column to keep a plain-text file listing every added and removed line, handy for a colleague or your own records.

No .pdf file to hand? Download a sample PDF file (6.3 KB) and try it.

Try it now

What Does PDF Comparison Show?

Comparing PDFs here means comparing their words. The tool reads the text of each page, rebuilds it into lines, and then works out the smallest set of additions and removals that turns the original into the new version. That is the same idea programmers use to review changes in code.

Because it looks at text, it catches rewording, deleted sentences, changed numbers and new paragraphs. It does not judge appearance, so a new font, a moved picture or a different page colour is not reported unless the words themselves changed.

PDF Document

.PDF

Two versions in, one clear view of every textual change out.

What people compare

Contract and agreement drafts
Resume versions
Revised syllabus or notices
Thesis chapters after review
Quotations and invoices
Policy and terms updates
Report drafts

Why Compare PDFs Instead of Reading Twice?

People are poor at spotting a changed word in a long page, especially one they have read before. A comparison does not get tired or skim. It shows every edit, including the quiet ones in the middle of a paragraph that change what a sentence means.

“The change that costs you money is rarely in the heading.”

Every edit made visible
Minutes instead of an hour
Changed figures stand out
Private documents stay private

Safer signing of contracts
Proof that nothing else changed
Jump straight to each edit
A saved record of changes

Popular Reasons to Compare PDF Files

Where a side-by-side check earns its keep.

Contract revisions Check a returned agreement before signing, so a changed notice period or fee cannot slip through.
Rental and loan papers Compare the draft you agreed with the final copy the bank or landlord sends for signature.
CV versions See what you changed between the resume you sent in March and the one you are sending now.
Updated notices Find what a college or exam board actually altered in a revised syllabus, schedule or circular.
Supervisor feedback Compare a thesis chapter before and after edits to see every sentence your guide rewrote.
Quotations Spot which line items, quantities or prices differ between two quotes from a supplier.
Policy updates Read only the changes in revised terms, HR policies or insurance wording.
Proofreading Confirm the printer’s final PDF matches the approved text word for word.

Compare PDF Features

Settings that let you decide which differences are worth your attention.

Layout

Split or unified view

See the two versions in columns, or in one column with removed and added lines one after the other.

Views:

Split
Unified

Precision

Word or character marking

Inside a changed line, highlight whole words, single characters, or let the tool choose automatically.

Noise

Ignore what does not matter

Hide spacing changes, capital letters and blank lines so only real edits remain.

Can ignore:

Whitespace
Capitals
Blank lines
Spaces at line ends

Focus

Hide unchanged lines

Collapse identical text and show only the edits with a little context around each one.

Navigate

Next and previous change

The ↑ and ↓ buttons beside a running count move you between edits without any scrolling.

Export

Download a .diff file

Save every added and removed line as a plain-text report you can share or file away.

Why Use ToolXkit to Compare PDFs?

Confidential by default

Agreements and offer letters are compared in the tab you are using. Neither version is handed to a server.

Compare PDF for Different Readers

Lawyers and paralegals

Check each round of redlines against the last agreed draft.

Business owners

Review supplier contracts and quotes before you commit.

Students and researchers

Track edits between thesis drafts and journal revisions.

HR teams

See what changed in policies and offer letter templates.

Editors and proofreaders

Confirm final proofs match the approved manuscript.

Home buyers and tenants

Make sure the paper you sign is the one you agreed.

Moments to Run a PDF Comparison

It is well worth a check when you are:

About to sign a revised agreement
Receiving a “final” version by email
Reading an updated syllabus or notice
Reviewing edits to your own writing
Comparing two quotations
Checking new terms and conditions
Approving a printer’s proof
Tidying up several CV versions

Tips for Accurate PDF Comparison

Scanned PDFs have no text to compare. Run both through OCR PDF first, then compare the searchable copies.
Keep Hide whitespace changes on when the two files were made in different programs. Layout spacing differs even when words do not.
On long documents, tick Hide unchanged lines and read only the edits.
Switch the highlight to Characters when you are hunting for a changed digit in an amount or date.
Remove a password with Unlock PDF first. A locked file cannot be read for comparison.
Remember that pictures, signatures and formatting are not compared. Look at those pages by eye.
Download the .diff before closing the tab if you may need to show someone what changed.

Frequently Asked Questions

Answers to common questions about this tool.

How do I compare two PDF files for differences?

Choose the older PDF under Original and the newer one under Changed version, then press Find the differences. Added text is shown in green and removed text in red, with arrows to move between the changes.

Can I compare two PDFs for free without Adobe Acrobat?

Yes. This tool compares the text of two PDFs in your browser at no cost, with no trial and no account. Acrobat’s compare feature is part of a paid plan; for checking wording, you do not need it.

Does it show changes in images or formatting?

No. It compares the words only. A new logo, a moved picture or a different font will not be reported unless the text also changed. Check pages with photos, stamps or signatures by eye.

Why does it say no readable text was found?

The PDF is almost certainly a scan, meaning each page is a photo with no text inside it. Make both copies searchable with our OCR PDF tool, then compare those new files here.

It says the files are identical, but they look different. Why?

The words match, so nothing readable changed. Differences in layout, fonts, colours or pictures are outside what this comparison looks at. With Hide whitespace changes on, spacing differences are ignored too.

Are my PDFs uploaded to compare them?

They are not. Both files are opened in this browser tab and the comparison is calculated locally. No copy is kept anywhere, so confidential agreements are fine to check here.

Can I compare password-protected PDFs?

Not directly. This tool cannot get past a PDF’s open password. Take the lock off first with our Unlock PDF page (you will need to know the password), then compare the unlocked copy.

How do I see only what changed?

Tick Hide unchanged lines in the settings column. Identical text collapses and only the edits remain, with a few lines around each so you can tell where it is in the document.

Can I compare a PDF with a Word document?

This page takes a PDF on each side. Export the document from Word as PDF beforehand, or use our Compare Word tool when both versions are .docx files.

Can I save the comparison?

Yes. Press Download .diff to save a plain-text file listing every added and removed line. It opens in Notepad or any text editor and is easy to attach to an email.

Does it work with large PDFs?

Yes, as far as your device’s memory stretches. Long reports of a hundred pages or more are fine on a computer. If the files are very large, the changed region may be shown as one block rather than line by line.

Can I use it on a phone?

It works on phones, but a side-by-side comparison needs room. Switch the Layout to Unified for a single column, or use a tablet or computer for long documents.

Is Compare PDF free, and do I need an account?

Yes. It costs nothing, and there is nothing to sign up for. Open the page, add your two files or paste two blocks of text, and the differences appear. There is no trial period and no limit on how often you compare.

Can I compare two different formats, like a PDF and a Word file?

Each compare tool is built for one kind of file, such as PDF, Excel, JSON or plain text. To compare across formats, convert one of them first, or copy the text of both into Compare Text.

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