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Compare Two PDF Files Online

Get a clear, downloadable diff of two PDFs - all in your browser.

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Drop your first pdf here or

Pick the original PDF (PDF A). You'll add the second PDF below.

How to Compare Two PDFs with IronFreeTools

  1. Upload PDF A

    Drop the first (original) PDF, or click to browse for it.

  2. Add PDF B & Pick Options

    Select a second PDF, choose text + metadata or metadata-only mode, then tweak the diff settings.

  3. Download Comparison Report

    A clean PDF report opens with per-page diffs.
    Download it to share with reviewers.

Compare Two PDFs

Go Beyond one-off PDF Comparison with IronPDF for C#/.NET

Compare PDF documents in your C# and .NET applications with IronPDF: extract text from each file, check differences page by page, and generate comparison reports.

Need PDF comparison inside your own app? IronPDF lets you extract and compare document text programmatically in C#/.NET.

Read the guide

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Frequently Asked Questions

Everything you need to know about comparing two PDF files

What does Compare Two PDFs do?

The tool extracts the text layer from each page of both PDFs, runs a line-by-line diff, and produces a comparison report PDF. The report highlights added, removed, and unchanged lines for each page and lists metadata differences such as title, author, and modification date.

Will it compare images or visual layout?

No. This tool focuses on the embedded text layer of each PDF and on document metadata. Scanned image-only PDFs without a text layer will return empty pages because there is nothing for the diff engine to read.

What does 'Ignore whitespace' do?

It collapses runs of spaces and tabs and trims line ends before comparing, so two lines that only differ in spacing are treated as identical. This usually cuts a lot of noise from documents that were re-exported.

What does 'Ignore letter case' do?

It lowercases both files before comparison so 'Total' and 'TOTAL' match. The original casing is preserved in the report; only the comparison key is normalized.

Why are some pages flagged 'Only in A' or 'Only in B'?

When the two PDFs have a different page count, the extra pages exist on only one side. The report shows those pages with a badge so you can see which side has the additional content.

Are my PDFs uploaded to a server?

No. Both files are read in your browser using pdfjs-dist and pdf-lib. The comparison runs locally and nothing is sent to a server.

Can I compare password-protected PDFs?

Encrypted PDFs need to be unlocked first so the text layer can be read. Use the free Unlock PDF tool on owned files before running the comparison.

Is there a page or file size limit?

No fixed limit. Long PDFs may take longer because the entire diff runs in your browser, so very large documents are constrained by your device's memory.

Do I need an account?

No. Compare Two PDFs is free to use without sign-up, login, or installation.

What are the key benefits?

Spot added and removed lines page-by-page See metadata differences at a glance Ignore whitespace and letter case noise Browser-only processing for sensitive documents Download a shareable PDF report No account, no watermark, no upload.