Read the bytes.
Not the promise.
One-time purchase. No subscription. Fourteen-day trial. macOS 13 and later.
Offline · Sandboxed · macOS 13+
Every byte, accounted for.
Finder reports the copy as succeeded the second the last byte flushes. It never reads the file back. VerifiedCopy does — re-reads every byte from the destination, matches it against the source, and only then says OK.
sha256 verifier · live
stream · 1.0.0
·IMG_2431.CR3sha256queued
·project.fcpbundlesha256queued
·birthday.movsha256queued
·archive_2025.tarsha256queued
01 · The interface
Three screens. One promise.
Selection, verification, integrity. Every operation is visible — not hidden behind a progress bar that tells you only what the OS believes.
02 · Pipeline
The bytes are made to prove themselves.
Three stages, in order. The destination cannot be silently trusted — it has to be read back, from disk, and matched against the source.
Stage A
01
Write
Source files stream to one or more destinations in parallel, with per-file and total progress.
Stage B
02
Re-read
Each file is read back from the destination drive itself — not from the write cache in RAM.
Stage C
03
Match
Source and destination SHA-256 are compared byte-for-byte. Any mismatch retries from the source.
03 · Origin
Why this tool exists at all.
A small field note from the maker. The whole application is downstream of a single, recurring, uncomfortable moment.
From the maker
Ting Tze Chuen · Maker of VerifiedCopyI kept copying videos to an exFAT drive, ejecting safely, and finding them corrupted on the TV.
macOS said the copy succeeded. Safe eject said the drive was safe. Neither actually reads the file back to confirm the bytes survived the trip. VerifiedCopy is the tool I wanted to exist — it copies, then re-reads every byte and tells you honestly whether the copy arrived intact.
04 · Principles
Six functions. Nothing else.
Every feature exists to serve byte-level integrity. If it can't be named in one sentence, it's not here.
Principle 01
Copy & Verify
Copy to one or many destinations; read each byte back; confirm the match. Default state, not a toggle.
Principle 02
Verify & Repair
Rewrite only the damaged blocks — not the whole file. Large archives stay quick when a few sectors fail.
Principle 03
Integrity view
A block map for any file. Healthy, damaged, and repaired regions are visible at a glance.
Principle 04
Fan-out
One operation, many destinations. A verified backup across several drives from a single instruction.
Principle 05
Offline, always
No network, no analytics, no accounts. Apple's macOS sandbox, and the files you explicitly select.
Principle 06
Native Swift
Lightweight. Efficient. Built for macOS. Feels like a part of the operating system, not a guest on it.
05 · Cases
Built for the people who can't afford to lose bytes.
Two populations feel the absence of verified copies most acutely — the archivists, and anyone handing a drive to a Windows machine.
Case A · Archival
Photographers, videographers, archivists.
Offload camera cards knowing every RAW arrived. Archive Final Cut Pro libraries with a verifiable receipt. Write to two drives at once and know both are clean.
Case B · High-risk
Mac → exFAT → Windows handoff.
Silent corruption on exFAT is a longstanding macOS issue — Finder will happily report a copy as successful even when bytes have been mangled in transit, especially with large files or drives shared between Mac and Windows machines. VerifiedCopy reads every copy back from the exFAT destination and compares it byte-for-byte against the original, so you catch corruption before you hand the drive off — not after a colleague opens it on Windows.
Q · A
Questions, answered plainly.
If it takes a paragraph to explain, the tool is probably doing too much. Everything here answers in a few sentences.
Q.01How does VerifiedCopy verify a copy?
Every file copied is read back from the destination drive and compared byte-for-byte against the source. If there's any mismatch, the copy is flagged and can be retried automatically.
Q.02What's the difference between VerifiedCopy and Finder copy?
Finder copies files but doesn't verify them afterwards. A damaged sector, flaky cable, or failing drive can silently corrupt a file during the copy and you'd never know. VerifiedCopy re-reads every copy and confirms it matches the original.
Q.03Does VerifiedCopy work with external drives, SD cards, and network volumes?
Yes. VerifiedCopy works with any drive macOS can mount, including external SSDs, HDDs, USB sticks, SD cards, and network shares.
Q.04Can VerifiedCopy help with exFAT corruption on Mac?
Yes — this is one of the most common reasons people install VerifiedCopy. Silent file corruption on exFAT drives is a longstanding macOS issue, especially with large files or drives shared between Mac and Windows. VerifiedCopy reads every copy back from the exFAT destination and compares it byte-for-byte against the source, so you know the file is intact before you hand the drive to a Windows machine.
Q.05What is silent data corruption or bit rot?
Silent data corruption (sometimes called bit rot) is when a file's contents change without any error message — caused by aging storage, faulty cables, or stray cosmic rays flipping bits. You often only notice when you try to open the file years later.
Q.06Is VerifiedCopy safe? Does it send data anywhere?
No. VerifiedCopy runs fully offline inside Apple's macOS sandbox. It makes no network requests, uses no analytics, and only accesses files you explicitly select.
Q.07Can VerifiedCopy repair corrupted files?
Yes. Verify & Repair scans existing copies against the originals and rewrites only the damaged blocks — not the entire file. That keeps repair fast, even for large archives where just a few sectors have gone bad.
Q.08What file types and sizes does VerifiedCopy support?
Any file, any size. VerifiedCopy verifies raw bytes rather than looking at file formats, so it works equally well for photos, videos, databases, archives, or any other type of file.
Q.09How is VerifiedCopy different from rsync or cp?
cp doesn't verify copies at all. rsync can verify with the -c flag, but you're in Terminal managing flags manually. VerifiedCopy is a native Mac app with checksum verification on by default, a visual progress view, multiple destinations in one pass, and a repair mode.