PDF Compare
Compare the text of two PDFs and highlight the differences
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
Original PDF
Changed PDF
About this tool
PDF Compare checks the text content of two PDF documents and highlights exactly what's different between them - added text, removed text, and changed wording. It's useful for reviewing contract revisions, comparing two drafts of a report, or verifying that a "final" version matches what was actually agreed on.
How to use this tool
- Upload both PDFsAdd original and revised document versions for side-by-side analysis.
- Run text comparisonExtract and compare wording across pages to detect changes.
- Review highlighted diffsInspect additions, deletions, and edits in context.
- Export findings or decisionUse result to approve, reject, or request clarification on revisions.
How to compare two PDFs for changes
Upload the original and the revised PDF. The text of both is extracted and compared, and the differences are highlighted: words added, words removed and passages that changed. It is the fastest way to check what changed between two versions of a contract, policy or report.
The comparison is of the text, not the layout, so moved images or new fonts are not flagged. Scanned PDFs have no text to compare - run them through OCR first.
Key features
- Catches subtle wording changes that are easy to miss manually.
- Speeds up legal, policy, and editorial review cycles.
- Useful for validating “final” versions before signature.
- Reduces risk from unnoticed contract term modifications.
Common uses
- Reviewing contract redlines before execution.
- Comparing policy document revisions between teams.
- Checking vendor-updated statements or reports.
- Auditing compliance edits in regulated documents.
Tips for better results
- Compare related versions, not unrelated files, for meaningful output.
- Focus first on changed numbers, dates, and obligations.
- Validate critical clauses manually even after automated diff.
- Keep version naming clear to avoid comparing wrong files.
Mistakes to avoid
- Assuming compare tool checks visual layout/image differences.
- Comparing unrelated files and misreading noisy diff output.
- Ignoring small punctuation/value changes in legal contexts.
- Skipping final human review for high-stakes agreements.
Frequently asked questions
It compares text content - wording that was added, removed, or changed between the two documents. It is not a pixel-by-pixel visual comparison of layout or images.
It works best comparing two versions of essentially the same document (like a draft and a revision). Comparing two unrelated documents will just show a large amount of difference, which is technically accurate but not very useful.
Changed text is highlighted so you can quickly scan for what was added or removed between the two versions.
Compare the version you agreed with the one you are asked to sign. Pay most attention to numbers, dates, names and words like 'not', 'shall' and 'may', where a small edit changes the meaning.
Only if it has text. Run scanned documents through OCR first; recognition errors may then show up as small false differences.
Reflowed text, different line breaks or hyphenation can make identical wording look different. Focus on highlighted words rather than line positions when two versions were exported from different programs.