Is this tool really free?

Yes, all our PDF tools are completely free to use with no hidden costs, subscriptions, or per-file charges. We support the service through non-intrusive advertising, not by charging for basic document operations. You can use any tool as many times as you like, with no daily limits, file size restrictions, or account requirements whatsoever.

Absolutely. All PDF processing happens directly in your browser using local JavaScript and WebAssembly libraries. Your files are never uploaded to any server, never stored in the cloud, and never transmitted over the internet. The files remain entirely on your device from start to finish, giving you complete control over your sensitive and confidential documents.

How does visual comparison work?

The tool renders each page of both PDFs as images and then performs a pixel-level comparison between the corresponding pages. Differences are highlighted in contrasting colors — typically red for content that appears in the first PDF but not the second, and green for content that appears in the second but not the first. This visual overlay makes it immediately clear where the documents differ.

Can I compare scanned documents?

Yes, visual comparison works on all PDF types including scanned documents, image-based PDFs, and mixed-content documents. Because it compares the rendered page images rather than text content, it does not require a text layer. This makes it particularly useful for comparing scanned contracts, signed documents, and any PDFs where the visual appearance is what matters most.

What is the difference between Compare and Visual Compare?

The Compare tool performs text-based comparison by extracting and comparing the text content from both documents. It excels at finding word-level changes in text-heavy documents with good text layers. Visual Compare renders pages as images and compares pixels, making it better for detecting layout changes, image modifications, font rendering differences, and changes in scanned documents.

Can small formatting changes be detected?

Yes, visual comparison detects even subtle changes including slight font weight differences, minor spacing adjustments, color changes, and small position shifts of elements. The sensitivity depends on the rendering resolution — higher rendering resolution detects finer changes but requires more processing time and memory. The default resolution is sufficient for most document review tasks.

What if the documents have different page sizes?

When the two documents have different page sizes, the comparison renders each page at a consistent resolution and aligns them for comparison. Significant size differences may cause many false positives since content positions differ. For best results, compare documents with the same page dimensions. If sizes differ, resize pages to match using the Resize Pages tool before running the visual comparison.

PDF Tools

Client-side processing

Organize

Merge PDF
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Rotate PDF
Page OrganizerNew
Reverse PagesNew
Insert PagesNew
Duplicate PagesNew
Interleave PDFsNew
Delete PagesNew
Extract PagesNew

Edit

Watermark PDF
Header & Footer
Add Page NumbersNew
Flatten PDFNew
Crop PDFNew
Sign PDFNew
Redact PDFNew
Stamp PDFNew
Add BackgroundNew
Bates NumberingNew
Add BookmarksNew
Add LinksNew
Add AttachmentsNew
Page LabelsNew
Add MarginsNew
Auto-CropNew
Remove AnnotationsNew
Fill PDF FormNew

Security

Encrypt PDF
Unlock PDFNew
Remove MetadataNew
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Analyze

Extract Content
PDF Statistics
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Edit MetadataNew
Repair PDFNew
PDF to TextNew
Extract AttachmentsNew
OCR PDFNew
Validate PDFNew
Visual CompareNew

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All processing happens in your browser. No files are uploaded to any server.

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