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.

looks_one

Original PDF

looks_two

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

  1. Upload both PDFsAdd original and revised document versions for side-by-side analysis.
  2. Run text comparisonExtract and compare wording across pages to detect changes.
  3. Review highlighted diffsInspect additions, deletions, and edits in context.
  4. Export findings or decisionUse result to approve, reject, or request clarification on revisions.

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.

Yes. Compare is free for normal use with no account required, and ToolBox does not add a watermark to your result.

Most tools in this category run in your browser so the file stays on your device. If a tool needs a temporary server job, files are handled for that job only and are not kept as a lasting archive.

No install needed. Open Compare in your browser, add your file or paste your input, then download or copy the result.

Yes on modern mobile browsers. For large files, a desktop browser is usually faster and more reliable.

Try a different quality or format setting, use a smaller input, or open a related tool (for example compress before convert). Keep a copy of the original file before replacing it.

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