draw - Flowchart Maker & Online Diagram Software draw (formerly Diagramly) is free online diagram software. You can use it as a flowchart maker, network diagram software, to create UML online, as an ER diagram tool, to design database schema, to build BPMN online, as a circuit diagram maker, and more. draw can import , Gliffy™ and Lucidchart™ files .Integrations · Support · About Us · Blog Block Diagram Maker | Free Online App & Download Create Block Diagrams Easily - Online or On Your Desktop. Block diagrams are easier with built-in block diagram templates and specific block diagram generating tools. Just start with a template and customize it using SmartDraw's large selection of symbols. Add lines and connectors and SmartDraw's automation will help your shapes remain connected and organized.