IntegrityChecker™ provides ultra-efficient validation of your data, including your originals and backups. Even single-bit errors are detected, anywhere in a file, using the cryptographic grade SHA1 hash.

IntegrityChecker is the perfect tool when moving data (backing up, switching systems, etc), because you can verify that all data has 100% fidelity to the original copy. And you can do so a day, a week or a month later, an important consideration if a system meltdown requires restoring all your data.

Both a GUI and a command-line interface are supplied. Most users will find the GUI suits their needs. For full control over test parameters, IntegrityChecker can be run in Terminal as a command line interface. For detailed usage information, please see the Integrity Checker User Manual.

Also, see Why Use It?.

How does it work?

IntegrityChecker™ creates one very small hidden file per folder (".ic")**, which contains the integrity-validation information for each file in that folder. There is no "database", and there is no modification to your files.

You choose which volume(s) or folder(s) you want to validate, running IntegrityChecker ("ic") on them. Later, the originals or any copies of the originals can be validated, because the .ic files "go along for the ride" when the folder(s) are copied or backed-up.

Of course, files often legitimately change, and here IntegrityChecker provides a report on which files changed and how, including flagging suspicious files that appear to be damaged. When files change, you can run IntegrityChecker on just the folders containing the changed files, to update their status appropriately. The validation detects detect flaky hardware that might sporadically generate bit errors in files, or software nasties, etc.

Mac OS X compatibility

IntegrityChecker is a single-file universal binary that runs on 32-bit or 64-bit systems. See the main page for details.

* Validation of files requires that you previously ran IntegrityChecker to generation validation data.

** The '.ic' file contains the integrity-validation information for each file in that folder, which is based on the 160-bit cryptographically strong Secure Hash Algorithm, SHA1. Which means that if a single bit changes, the odds of missing it are incredibly small — you're more likely to win the lottery.