Curated collection
7 handpicked diagrams tools with curated descriptions — free to browse, no signup. Also available as an interactive tab on the Lumina homepage.
Flowchart.fun is a free, open-source online tool that generates flowcharts from plain text inputs. No sign up required — write your flowchart structure using simple syntax, and the tool automatically renders it visually. Export diagrams as PNG, SVG, or share via a unique URL.
Mermaid Drawing is a free online tool for creating flowcharts, sequence diagrams, Gantt charts, and other diagrams using Mermaid.js syntax. Write simple text code and instantly preview beautiful diagrams, then export as SVG, PNG, or PDF.
Mermaid AI is an AI-powered diagramming tool that generates Mermaid.js diagrams from natural language prompts. Describe your flowchart, sequence diagram, or architecture visually using text, and the AI creates the diagram code automatically.
DGM is a free online sketchnotes and diagramming tool for professionals, supporting smart shapes, UML, ERD, flowcharts, real-time collaboration, and AI-powered code generation from diagrams. Free forever for local use.
DrawDB is a free, open-source online database diagram editor and SQL generator. Create entity-relationship diagrams (ERD), visualize database schemas, and automatically generate SQL code with an intuitive drag-and-drop interface. No registration required.
Virtual whiteboard with a hand-drawn aesthetic for sketching diagrams, architecture, and flows. Real-time collaboration, an infinite canvas, and libraries of community-made shapes — free and open source, with everything running client-side in your browser.
Delightful collaborative infinite-canvas whiteboard that works instantly in the browser. Snap-to-shape drawing, arrows that stay attached, rich shape and text tools, and multiplayer cursors. Also available as an SDK if you want to embed a canvas in your own product.