Here I look at five tools that provide online modeling services, ranging from commercial products to free, open-source solutions. They include Vertabelo, GenMyModel, dbDiffo, WWW SQL Designer, and DbDesigner.net. Each one takes a different approach to delivering its services and completing basic tasks, such as adding tables, columns, or relationships. You’ll find that some tools are more feature-rich and user-friendly than others, but each one has its own advantages and charms.
That said, none of the tools provide the level of functionality you get with an advanced on-premises solution such as PowerDesigner or ER/Studio, but not everyone needs such an extensive set of features—or the price tag that goes with them. In fact, all five online tools come either completely free or have a free version available, making it possible to try all of them without having to commit one way or the other. Not surprisingly, the free versions associated with the commercial products have limitations on their use.
The hat I’d throw into the ring is draw.io. It’s a Visio look-alike, so it’s more useful for high-level strategic diagrams than a true model.