Find what changed before it costs you.
Keep A/B/C+ PDF revisions in one private timeline, compare any pair on device, review each detected difference, and export lineage-aware evidence.
Local PDF comparison
PDFKit extraction, on-device Vision OCR, and rendered-page checks run without an account, backend, or document upload.
Revision timeline
Add later PDFs to the same project, compare any two stored revisions, and reopen reusable comparison snapshots.
Revision lens
Drag a clear Version A and Version B divider over the real PDF page while the selected difference stays highlighted.
Human review queue
Move through additions, removals, replacements, page changes, and visual differences, then mark each Pending, Expected, Flagged, or Ignored.
Portable evidence
Create a highlighted redline PDF, spreadsheet-ready CSV, or JSON archive containing hashes, revision lineage, snapshots, and review state.
How it works
Choose Version A and Version B from Files. Review the progressive local comparison, add later revisions to the timeline, compare any stored pair, and export the evidence.
Private by design
No account, backend, cloud sync, analytics, advertising, tracking, external AI, or document-upload service is used.
Pricing
ChangeProof is a one-time paid App Store download. The app has no in-app purchases, subscriptions, trial paywall, or external checkout.
FAQ
ChangeProof assists document review. It cannot certify completeness or guarantee that every difference will be detected.
Are my PDFs uploaded?
No. Imported revisions, OCR output, detected changes, source hashes, cache records, review status, and exports are processed and stored in the app container.
Can ChangeProof compare image-only or scanned PDFs?
Yes. On-device Vision OCR supplements image-only pages and uncovered scan regions in mixed-content pages, while rendered visual comparison remains available. Always verify important revisions in the source PDFs.
Does ChangeProof guarantee every difference?
No. It is a review assistant, not certification. Confirm important changes against both source documents before relying on the result.
Does comparison work offline?
Import, OCR, analysis, revision timelines, review, deletion, and export do not require an account or developer server. Public support links require internet access only when opened.
ChangeProof
ChangeProof is built for iPhone and iPad as a one-time paid App Store download.