Last week we wrote about how you can use hashes to scan files for viruses using VirusTotal, and referenced a few ways to grab the hashes on both Windows and Mac. One of the recent additions to my portable catalog is a hash calculator called HashMyFiles put out by Nirsoft, who makes a lot of great freeware utilities.

What’s so great about HashMyFiles? For one it doesn’t require any installation, but on top of that it includes all of the features you’ll find in similar apps… plus some. The first time you run it you’ll probably want to go to the Options menu and enable the Explorer context menu. That way you’ll be able to right-click on files in Windows Explorer and have it calculate the MD5, SHA1, and CRC32 hashes for it. You can also select multiple files and the program will calculate out hashes for all of them.

One feature you won’t find in many of the other apps is the report generation. This will let you selectively save off hashes to an HTML file that you can safely tuck away. When would this be useful? The first thing that comes to my mind is if you want to keep tabs on whether or not some files have changed. Using the report you can compare the current hash to the one from the archived report.

If you’re a command line guru you may enjoy the fact that the included executable also has a variety of DOS-compatible commands available for all your scripting needs.

For those of you wondering the executable weighs in under 50KB, and uses under 2MB of memory when running.

HashMyFiles Homepage (Windows only; Freeware)