There are multiple online tools that can be used to generate and compare hashes, but the steps below will cover how to complete this when using a tool named HashTab (Version 6.0.0.34) on Windows 10. (Please note: HashTab offers a free version for personal, non-commercial use only. Please use the appropriate license if you plan to use their tool.)
Step 1: Open a browser and navigate to the HashTab download page here.
Step 2: Download the free version, and complete the installation procedure.
Step 3: Once installation is complete, download our Pi 3/3B+ image here, and our MD5 file here.
Step 4: Once both of these files are downloaded, navigate to the zip file that contains the image, right-click on this zip file, and select Properties.
Step 5: Click on the File Hashes tab, and the tool will automatically generate the hash value for you.
Step 6: Once the hash is generated and visible, click the Compare A File button, and select the MD5 file you downloaded previously.
Step 7: The tool will now compare the hash of the zip file with the hash of the MD5 file, and should display a green checkmark if these are a match.