Visio was the tool I used back in the day to create flowcharts, diagrams, and other similar visuals I included in numerous print books and manuals I wrote and published. Those needed to look really professional, and Visio delivered.
I mention Visio because that’s exactly the tool I’m reminded of when I use diagrams.net to create the same exact kinds of charts and diagrams, but this time online and totally free. I’m consistently impressed by the tools available to us on the Web at no cost nowadays.
You’ll want to spend a bit of time to get acclimated to how it works—this thing’s powerful and has a lot of features—but it really didn’t take me too much time at all (without reading instructions) to figure it out enough and pump out the sample image below:
Not too bad at all for a first try, and I barely know the tool’s features, or even how to use it well for that matter, but here we are. Go check it out.