I suggest having a read of : https://www.di-mgt.com.au/sha_testvectors.html This has some standard test examples to test the hash algorithm and software. The line for the input abc is: SHA-3-256 3a985da74fe225b2045c172d6bd390bd855f086e3e9d525b46bfe24511431532 So, if your Windows program, such as quickhash, produces this same result for the 3 character input abc, then it is acceptable. Make sure you input is EXACTLY 3 characters. No spaces, tabs,line feeds or carriage returns. It may take a few tries to get the right parameters - as you can see from the above sha_testvectors site there are at least 9 combinations.