Top 10 Best Mermaid Diagram Tool Software of 2026

Miro brings Mermaid diagrams into a collaborative visual workspace: teams can paste existing code, start from a template, or use an MCP-connected agent to create and update diagrams. The site describes direct canvas editing of shapes, two-way changes through MCP, and real-time collaboration, while keeping edits exportable as standard Mermaid syntax.

This combination suits engineering teams that want to make technical diagrams understandable and editable for colleagues beyond the code author. A concrete tradeoff is that its collaborative canvas adds a workspace around Mermaid rather than serving only as a minimal code editor; it fits a design review where developers and product managers need to inspect and discuss a flow together.

Obsidian stores notes as Markdown files in a local vault, and its plugin API lets developers extend workflows around those files. Mermaid diagrams stay readable as source text and render inside notes.

Diagram construction is text-first, so users who need to drag nodes into place may prefer a dedicated visual editor. For architecture notes and runbooks, keeping Mermaid source beside explanations and linked references keeps the diagram in context.

Structurizr keeps architecture elements and relationships in one model, then uses views to present system context, containers, components, and deployments. Teams can define workspaces with the Structurizr DSL, add documentation and architecture decision records, and use the CLI in Git-based workflows.

The model-first approach requires teams to learn Structurizr’s DSL and C4 concepts before producing diagrams. It suits architecture groups that want consistent views of a software system and Mermaid exports for documentation, but not users who need unrestricted free-form diagram editing.

Eraser brings Mermaid editing into a collaborative technical-diagram workspace, pairing code-based authoring with a visual canvas. Teams can create flowcharts, sequence diagrams, and entity-relationship diagrams, then share them alongside documentation.

Excalidraw converts Mermaid markup into editable diagrams on a hand-drawn canvas instead of keeping source code as the main editing surface. Users can adjust converted shapes and connectors, add freehand sketches, and export boards as PNG, SVG, or Excalidraw files.

GitBook suits software teams that need Mermaid diagrams embedded in maintained documentation rather than on a standalone canvas. Its block-based editor renders Mermaid syntax alongside API references, code samples, and prose, while Git Sync connects documentation workflows to GitHub and GitLab repositories. Teams can organize content into spaces, collaborate on edits, and publish documentation sites with search and access controls.

Mermaid Live Editor pairs editable diagram syntax with an immediate rendered preview instead of a drag-and-drop canvas. It supports flowcharts, sequence diagrams, class diagrams, state diagrams, entity-relationship diagrams, and Gantt charts, with syntax highlighting in the editor.

Among text-based diagram services, Kroki is distinct for routing diagram source through one HTTP API that supports Mermaid and dozens of other syntaxes. Teams can submit Mermaid text with GET or POST requests and receive rendered output such as SVG or PNG.

PlantUML converts text descriptions into UML and other diagrams, keeping diagram source editable alongside code. Its syntax covers sequence, class, activity, component, state, deployment, and network diagrams, with output in formats such as PNG and SVG.

Mermaid Chart gives engineering and documentation teams a browser-based workspace for editing Mermaid diagrams, pairing a visual editor with editable diagram source. It supports flowcharts, sequence diagrams, class diagrams, ER diagrams, Gantt charts, and mind maps, with a live preview as the source changes. Teams can share and collaborate on diagrams, then export visuals for use in documentation.