Copied. Verified. Proven.
HashCopy copies cards and drives on your Mac and checks every file by hash - reading back from the destination what it just wrote.
macOS 13 or later · Apple Silicon and Intel
Macintosh HD›NIKON ZR›LaCie Backup›The Finder says it copied. It verified nothing.
The Finder never rereads the file at the destination
It passes along what the operating system reported. Block written, marked as written, move on. No read back, no comparison.
Silent corruption gives no warning
A bad cable, a failing reader, an interrupted write, bit rot. The file arrives different from the original and the progress bar ends the same way, with the same green check.
You find out weeks later
The error shows up in the edit, once the card has been formatted and the only copy of the footage is the corrupted one.
A copy is only right when you can prove it.
Hashing is what turns "I think it copied" into a verifiable statement. It is the basis of everything HashCopy does.
A fingerprint of the file's contents.
A hash is a mathematical operation that reads the whole file and returns a fixed-size value. The same contents always produce the same value. A single different bit produces a completely different value - not similar, different.
Both files have the same size, the same name and open the same way. One bit of difference is enough for the fingerprints to have nothing in common. That is why hash comparison catches what the eye and the file system do not.
Reads, copies, rereads and compares.
Verification does not look at the system's report. It reads the file that ended up on the destination back from the disk and calculates the hash again.
Reads the source
The file is read in full from the source card or drive.
Source hash
The contents read produce the first fingerprint.
Copies
The file is written to the destination.
Rereads the destination
The written file is read back from the destination, not from cache.
Compares
The second fingerprint is compared against the first.
xxHash64 by default. MD5 when someone requires it.
xxHash64 was built to check integrity, and it is fast enough never to be the bottleneck: no drive in existence reads faster than it computes. It is the de facto standard among DIT tools, so the same number comes out the same elsewhere.
MD5 is available too, for when a delivery contract or an older workflow requires MD5. It is considerably slower and no safer against accidental corruption - it is here for compatibility, not for quality.
What comes in the app.
Hash verification by default
Every copy is checked by reading the file back from the destination. You can pick a stricter mode that re-reads the source too, or a faster one that checks only file size.
A report for every transfer
Each copy records the files, the hashes and the result of the comparison in a Hash Log folder inside the destination itself.
MHL generation
Media Hash List, the industry standard for DIT workflows, written alongside the text report.
Built-in drive browser
Source, destination, renaming and new folders inside the app, without going through the Finder.
Transfer queue
Several copies queued up, each with its own progress, speed and state.
Native macOS interface
A native app, with light and dark themes following the system.
Finder and HashCopy.
One licence, two machines.
Two machines included. No subscription: the licence is yours and does not expire.
Buy a licenceFor teams with more stations. Add as many as you need to the same licence.
The full app, with no feature limits. No credit card required.
Questions.
Does this make copying slower?
Is this the same as a checksum?
Do I need to be a DIT to use it?
Is it for offloading memory cards on set?
Can I format the card afterwards?
Does it work with any card or drive?
Where are the reports kept?
Does it run on Intel?
Copy knowing it arrived intact.
Download HashCopy and run your next offload with the copy verified end to end.
Download for MacmacOS 13 or later · Apple Silicon and Intel · version 1.1.6 · 3,3 MB