CrcCheckCopy is a portable app that allows you to compare the files of different folders from the command line.
CrcCheckCopy generates a CRC32 for each file, storing it in a single checksum file. You can then use this small file for checking/comparing another folder hierarchy; You can also use it for an integrity check of the same folder hierarchy. CrcCheckCopy compares files in binary mode, ensuring that the files are exact, identical copies.
The checksum file enables you to compare folders on two remote computers without transferring the whole folder structure over the internet. Other similar comparison utilities need concurrent access to both folder hierarchies and need to read (again) the files of the source directory.
Compare file contents and verify them
Finds zero-sized files
Finds duplicate files (since ver 2.2), even if they have different filenames and different extensions and are stored in completely different folders
Creates the CRC hash of each file (like a digital signature of the file)
Creates a single file with the CRC hashes of every file. This file can be used to compare another folder, or to verify the same folder in the future: to make sure that no file was deleted in the meantime or has been altered. In this way, it adds a digital signature to the whole folder structure and its files
No need for concurrent access to the two folders that must be compared
No need for network connection or internet bandwidth when comparing folders on remote computers: Only the CRC signatures file needs to be transferred between them. The program will run locally
Ensure integrity of backups: You can store the CRC file together with the backup and you will be able to validate the integrity of the files and their contents at any time in the future
Cross-platform (Windows, macOS)
Continue the comparison on another Operating System: Let's you compare a folder structure on Windows with its backup copy on a Mac/MacBook
Creates a report file with the comparison results, the zero-sized files, and the duplicate files found
The report is in plain text so you can further process or parse it with other tools, e.g. import it to excel