Preflight before writing
OffloadProof checks that all three folders are distinct and not nested, confirms destination write access and available capacity when reported, and warns when both destinations appear to share one storage volume.
Private dual-copy utility
Copy once to two destinations. Verify every file.
Choose one source and two destinations in Files. OffloadProof copies every regular file, reads both copies back, compares SHA-256 checksums, and exports a result you own.
Local-first · Source read-only · No accountBuilt for a careful card or drive offload
Two atomic destination copies
Each file is copied through a temporary file before it is committed to Copy A, then Copy B. The selected source is never deleted, formatted, renamed, or modified.
Read-back SHA-256 verification
OffloadProof hashes the source, reads each finished destination file back, and compares all three SHA-256 values. A changed source or mismatch is shown as an issue.
Exportable evidence
Completed sessions can export a readable PDF, a portable CSV table, and a SHA-256 manifest through Apple’s share sheet.
How it works
Choose three folders
Select one source folder and two destination folders with Apple’s Files picker, then name the session.
Review preflight
Confirm file count, total size, destination capacity, write access, and any storage-volume warning before starting.
Keep drives connected
The app copies, reads back, verifies, and checkpoints after each fully verified file. You can pause or cancel safely.
Inspect and export
Review every file and checksum, then export the PDF, CSV, and SHA-256 manifest to a destination you choose.
A narrow privacy boundary
There is no OffloadProof account, backend, cloud sync, advertising, analytics, tracking, crash-reporting SDK, or external AI. Folder bookmarks, session history, and verification results stay in the app container. A File Provider you choose may use its own network service; OffloadProof does not send files to a developer server.
One paid download
OffloadProof is a paid App Store download. There are no subscriptions, in-app purchases, ads, external checkout, or paid feature gates inside the app. Apple displays the price and currency for your storefront before download.
Frequently asked questions
Can OffloadProof erase my source media?
No. The source is opened read-only for enumeration and hashing. OffloadProof never deletes or formats it.
What happens when a destination file does not match?
The mismatch remains visible and is not overwritten automatically. Replacing a mismatched destination file requires a separate confirmation.
Does the core workflow require internet access?
No OffloadProof server is required. A File Provider selected in Files may need network access under that provider’s terms. Public help links also require web access when opened.
What does a verification report prove?
It records that the selected files matched at verification time. It is not a permanent backup guarantee, forensic certificate, or legal chain-of-custody record.
Built for iPhone and iPad
OffloadProof 1.0 supports iOS and iPadOS 18 or later. App Store availability follows Apple’s review.
Read support information