Compare PDFs highlights every textual and structural difference between two versions of a file — added, removed, or changed text, moved paragraphs, and page-level changes — side by side, for reviewing contract redlines or catching unauthorized edits.
| You want to… | Use this tool |
|---|---|
| Added text | A new clause 12.3 appears in the revised draft |
| Removed text | A liability cap is deleted |
| Changed text | "30 days" becomes "45 days" |
| Moved text | Clause 7 now sits after clause 9 — shown as a move, not a delete plus an add |
| Page changes | A page is inserted, and the rest of the comparison stays aligned |
Lawyers compare original and revised contracts to spot every addition, deletion, and clause change before client review.
Researchers compare pre- and post-peer-review drafts to verify all reviewer comments were addressed in the revision.
Engineers compare published vs updated technical specs to identify breaking changes for downstream systems.
Add the original first, then the revised file.
Changes are found in seconds — even if pages were added or removed in between.
Added, removed, changed and moved text are marked side by side, with a summary list of every change.
Download a marked-up PDF or HTML report to share with your team or the other party.
Yes — the comparison re-aligns content even when the page count differs between the two files.
Standard text diff identifies word-level changes. Semantic comparison (Claude Sonnet 4.5) catches reworded passages with unchanged meaning. Visual overlay detects layout and image differences.
Yes. Scanned PDFs trigger OCR before comparison. Best accuracy from clear scans at 300+ DPI.
Yes. The compare tool detects content language automatically and compares within the same language. Translated versions can be compared semantically.
Markup PDF (changes highlighted inline), side-by-side HTML report, JSON diff for programmatic processing, and PDF summary report.
Yes. Move detection identifies paragraphs that shifted location without text changes — useful for spotting reorganized sections.
5 MB each on guest, 100 MB each on Pro, 500 MB each on Business. Documents with 1000+ pages are supported.
No. Anthropic's API does not train on customer data. Compared PDFs are private and auto-delete in 24 hours.
3 comparisons per day on guest and free accounts. Pro gets 50/day, Business unlimited. No credit card for any tier.
Identifies whether your content was written by AI or a human.
Scans your text and corrects grammatical errors and writing mistakes.
Translates your PDF content into another language while keeping formatting.
Rewrites AI-generated content to sound natural and human.
