How to Compare Two PDFs
When reviewing contract revisions, proof iterations, or updated reports, you need to see exactly what changed between two versions of a PDF. Reading both documents side by side is slow and error-prone—differences in single words, numbers, or formatting are easy to miss. SublimePDF's comparison tool highlights every difference between two PDFs, including text changes, added or removed content, and formatting modifications.
Follow the step-by-step instructions below, then use the free tool directly — no registration or download required.
Open Tool →How to Compare Two PDFs — Step by Step
Upload both PDF versions
Open the Compare PDFs tool and upload the original document in the left panel and the revised version in the right panel. Label them clearly so you know which is the baseline.
Select comparison type
Choose 'Text comparison' to focus on content changes (words added, deleted, modified), 'Visual comparison' to overlay pages and highlight any pixel-level differences, or 'Combined' for both.
Review the difference report
The tool generates a page-by-page comparison with color-coded highlights: red for deleted content, green for additions, and yellow for modifications. A summary sidebar counts changes by type.
Navigate between changes
Use the 'Next change' and 'Previous change' buttons to jump between differences. Each change is annotated with the page number and the specific old vs. new content.
Export the comparison report
Download a comparison report PDF that includes both the annotated pages and a written summary of all changes. This is useful for stakeholder review or audit trails.
Pro Tips
- 💡 For contracts and legal documents, use text comparison mode—it catches single-word changes that visual comparison might miss if the layout didn't shift.
- 💡 Visual comparison is better for design-heavy documents (brochures, flyers) where layout, image, and color changes matter as much as text.
- 💡 If the two PDFs have different page counts, the tool aligns matching pages and flags inserted or deleted pages separately.
- 💡 Export the comparison report and attach it to your email when returning feedback—it gives the other party a clear view of what you found.
Privacy & Security
All processing happens directly in your browser. Your files are never uploaded to any server — they remain on your device throughout the entire process. SublimePDF uses WebAssembly technology for fast, secure, client-side processing.
Works Everywhere
This tool works on any modern browser — Chrome, Firefox, Safari, or Edge — on desktop, tablet, or mobile. No software to install. PDF is an open ISO standard supported by all major platforms.
How to Compare Two PDFs — FAQ
Can I compare PDFs with different page sizes?
Does it detect formatting changes like font or color differences?
How does it handle scanned PDFs?
Can I compare more than two versions?
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