Fast Files Integrity Checker for Windows

Welcome to the easiest and fastest MD5 software project. Make and check fingerprints of your important files using the #1 integrity control algorithm.


FastSum lets you create fingerprints of your data in three ways. You can choose between the easiest step-by-step wizards, main application or a command line utility, run it from the Explorer context menu in two clicks. This makes FastSum stand out against all the other MD5 software.


In-depth optimization drives verification process in your hardware to a physical limit. FastSum is designed to process a huge number of files, entire drives or mass storage systems with minimum CPU load.


Be sure of your files integrity, find changes, and track errors using time-proven cryptographic MD5 algorithm - a result of longstanding work of one of the most famous cryptographers, Ronald Rivest.

Shell integration

The shell integration features in FastSum let you quickly check integrity of several folders or entire drives by easy step-by-step Wizards. You also can visually compare last fingerprint with actual, copy it to clipboard and post on your web site.

Global shortcut keys

When you are installing the full software package, you can also install the global shortcut keys to run FastSum faster.

Free Download! The two integrity checkers based on cryptographic approved MD5 checksum algorithm in the one package!
Subscribe to our newsletter to receive information on new releases, and updates. Your e-mail address will not be used for other purposes nor shared with others.