Help with local PDF revision timelines, on-device comparison, review, and export.
Start with an earlier PDF as Version A and a revised PDF as Version B. Later, open the revision timeline to add more PDFs or compare any two stored revisions.
Getting started
Start with an earlier PDF as Version A and a revised PDF as Version B. Later, open the revision timeline to add more PDFs or compare any two stored revisions.
Files and PDF import
ChangeProof uses Apple's Files picker and reads only PDFs you explicitly select. Make sure iCloud files are downloaded before choosing them.
Comparison and review
The app aligns pages, compares embedded text, supplements scanned regions with on-device OCR, and checks rendered visuals. Drag the lens and mark each change Pending, Expected, Flagged, or Ignored.
Export and sharing
Create a redline PDF report, CSV change log, or JSON archive containing source hashes, revision lineage, comparison snapshots, review state, and limitations, then use Apple's share sheet.
Revision history and deletion
Projects and revision timelines remain in the app container. Delete one project from History, or delete all local projects and their cached analysis in Settings.
Purchase model
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.
What if a PDF is password-protected?
Unlock and save a copy in Files before importing it. ChangeProof does not ask for, store, or recover PDF passwords.
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.
Troubleshooting
If import fails, confirm the file is a valid, non-empty, unlocked PDF and fully downloaded in Files. Then choose it again. If a page cannot render, save a fresh PDF copy from its source app. Large documents are processed progressively; unchanged page work may be reused from the private local cache. If export fails, confirm the device has available storage, reopen the project, and create the format again.
Contact
Email support@vshia.com with the app version, device model, iOS version, and steps to reproduce the issue. Do not attach confidential PDFs unless you intentionally choose to share them. We normally reply within two business days.