Visualize Ideas with Code
The simplest way to create diagrams. Just type Mermaid syntax and see your diagrams come to life instantly.
Powerful Features for Modern Diagram Creation
The simplest way to create diagrams. Just type Mermaid syntax and see your diagrams come to life instantly.
Live Preview
The editor renders your diagrams in real-time as you type, giving you instant feedback on your syntax.
Multiple Formats
Support for Flowcharts, Sequence Diagrams, Gantt Charts, Class Diagrams, State Diagrams and more.
Code-First
Keep your diagrams version controllable and easy to edit. No more dragging and dropping pixel-imperfect boxes.
No Sign-Up Required
Start creating diagrams immediately in your browser. No account registration, no downloads, no installations needed.
Version Control Friendly
Store your diagrams as plain text in Git. Track changes, collaborate with teams, and maintain diagram history effortlessly.
Easy Export
Copy your Mermaid code to use in Markdown files, GitHub READMEs, documentation sites, or any platform supporting Mermaid.js.
How to Use the Mermaid Editor
Write Your Code
Enter Mermaid syntax in the code editor on the left. Start with a diagram type like 'graph TD' for flowcharts.
Preview Instantly
Watch your diagram appear in real-time on the right panel. Changes are rendered automatically as you type.
Use Templates
Click on Flowchart, Sequence, or Gantt buttons to load sample code and learn the syntax quickly.
All Diagram Types Supported
Create any type of diagram with simple text syntax
Flowcharts
Visualize processes, workflows, and algorithms with nodes and directional arrows. Perfect for business processes and decision trees.
Sequence Diagrams
Document interactions between different actors or systems over time. Ideal for API documentation and system design.
Class Diagrams
Model object-oriented systems with classes, attributes, and relationships. Essential for software architecture planning.
State Diagrams
Represent state transitions in systems or applications. Great for modeling lifecycle states and workflows.
Gantt Charts
Plan and track project timelines with tasks and dependencies. Perfect for project management and scheduling.
ER Diagrams
Design database schemas with entities and relationships. Ideal for database modeling and documentation.
User Journey
Map user experiences and interactions across touchpoints. Excellent for UX design and customer journey mapping.
Git Graphs
Visualize Git branching strategies and commit histories. Helpful for explaining version control workflows.
Perfect for Every Use Case
Whether you're a developer, designer, or project manager, our Mermaid editor has you covered
Software Developers
Document code architecture, design patterns, and system flows. Embed diagrams directly in your GitHub README or technical documentation.
Project Managers
Create Gantt charts for project planning, flowcharts for process documentation, and timeline visualizations for stakeholder presentations.
Educators & Students
Explain complex concepts with clear visual diagrams. Create educational materials, study guides, and course documentation.
Technical Writers
Enhance documentation with professional diagrams. Keep visual assets synchronized with code using version-controlled text files.
Why Choose Our Mermaid Editor?
The best online tool for creating diagrams from code
100% Free Forever
No premium tiers, no feature locks, no time limits. All features are completely free with unlimited diagram creation.
Privacy Focused
Your diagrams are processed locally in your browser. We never store or access your diagram code on our servers.
Fast & Responsive
Optimized for performance with instant rendering. Work smoothly even with complex diagrams containing hundreds of elements.
Always Up-to-Date
Built on the latest Mermaid.js library with support for all modern diagram types and syntax features.
Benefits of Text-Based Diagrams
Discover why developers and teams love code-first diagramming
Maintainable Documentation
Unlike image-based diagrams that become outdated, text diagrams can be updated as easily as changing a line of code.
Seamless Collaboration
Review diagram changes in pull requests, track modifications in Git history, and resolve conflicts just like code.
Automated Integration
Generate diagrams automatically from CI/CD pipelines, integrate with documentation generators, and keep visuals in sync with code.
Consistent Styling
Mermaid applies consistent styling automatically. No more time wasted aligning boxes or choosing colors manually.
Frequently Asked Questions
Mermaid is a JavaScript based diagramming and charting tool that renders Markdown-inspired text definitions to create and modify diagrams dynamically. It lets you create flowcharts, sequence diagrams, class diagrams, state diagrams, and more using simple text syntax.
Yes, this online Mermaid editor is completely free to use. There are no hidden fees or premium features. You can create unlimited diagrams and use all the features without any restrictions.
You can copy the Mermaid code directly from the editor to save it in your own files. The code can be pasted into any Markdown file, GitHub README, or documentation that supports Mermaid rendering.
The editor supports all Mermaid.js diagram types including Flowcharts, Sequence Diagrams, Gantt Charts, Class Diagrams, State Diagrams, Entity Relationship Diagrams, User Journey Maps, Git Graphs, and Pie Charts.
Absolutely! Diagrams created with this editor can be used for any purpose including commercial projects, presentations, documentation, and educational materials.
No installation required! This is a browser-based online Mermaid editor. Simply visit the website and start creating diagrams immediately. It works on all modern browsers including Chrome, Firefox, Safari, and Edge.
Unlike traditional drag-and-drop diagram tools, our Mermaid editor uses a code-first approach. You write text-based syntax to define diagrams, which makes them version-controllable, easy to update, and perfect for including in documentation alongside your code. This approach is faster for developers and keeps diagrams consistent with your codebase.
The primary export format is the Mermaid code itself, which can be rendered as images by platforms that support Mermaid.js such as GitHub, GitLab, Notion, and many documentation generators. You can also use browser screenshot tools to capture the rendered diagram.
The initial load requires an internet connection, but once the page is loaded, the diagram rendering happens entirely in your browser. Your diagram data never leaves your computer, ensuring privacy and security.
Our editor includes sample templates for common diagram types like flowcharts, sequence diagrams, and Gantt charts. Click the template buttons to load examples and learn the syntax. The official Mermaid.js documentation also provides comprehensive guides for all diagram types and advanced features.
Start Creating Diagrams Today
No sign-up required. Just start typing and watch your ideas come to life.