Class Diagram Generator
UML diagrams from plain text, instantly.
Describe your domain model and AI builds a clean UML class diagram in seconds. Add stereotypes, visibility, and relationships, then export as SVG or PNG.
Why use this class diagram generator
AI-powered UML modeling with precise, professional controls.
AI-first modeling
Describe your domain in plain text and get a complete, ready-to-edit UML class diagram in seconds.
Smart relationships
Choose inheritance, composition, aggregation, association, dependency, or realization and label with cardinality like 1..* or 0..1.
Stereotypes and visibility
Mark classes as interface, abstract, enumeration, or service; set member visibility per field and method.
Auto layout
Diagrams are arranged automatically to minimize line crossings and keep your model readable.
Clear labels and titles
Editable chart title and concise class, member, and relationship labels for instant understanding.
Zoom and font control
Pan the canvas, zoom in for details, and adjust font size for presentations or deep code reviews.
Add your model
Type classes
Enter class names, members, types, visibility, and stereotypes directly into the editor.
Paste definitions
Paste existing class definitions and AI maps members and relationships for you.
Describe with AI
Write a short domain description and get a full draft diagram ready to refine.
Use a sample
Start from Animal, Duck, and Fish to learn the tool in under a minute.
Share and export
Download SVG/PNG
Export crisp, high-resolution diagrams ready for slides and documentation.
Share a link
Send a view link to teammates or stakeholders with a single click.
Embed on any site
Add a live, auto-updating diagram embed directly to your webpage.
Async collaboration
Collect feedback on diagrams without sending large files back and forth.
About this class diagram tool
Skip the drag-and-drop grind. Describe your model in plain text and AI produces a clean, standards-compliant UML class diagram instantly. Edit members, stereotypes, and relationships with simple controls. Preview every change live and export in high quality.
- ✓Optimized for fast UML modeling
- ✓AI that follows UML notation rules
- ✓Labeled cardinalities on every relationship
- ✓Auto layout with minimal line crossings
- ✓One-click export, share, and embed
Quick facts
How it works
From plain text to polished UML in minutes.
Describe or start blank
Type what you need or open an empty canvas to build your class diagram manually.
e.g. 'Animal has name:String; Duck inherits Animal; Fish uses Fin with 1..* composition.'
Define classes and members
Add class names, stereotypes, and members with types, return types, and visibility modifiers.
Animal {+name:String, +eat():void}; Duck {+quack():void} stereotyped as interface.
Set relationships
Pick a relationship type and add optional labels or cardinalities between classes.
Duck inherits Animal; Fish has composition to Fin with cardinality 1..*.
Export or share
Set your title, adjust font size, then download SVG/PNG or share a link and embed code.
Title: 'Aquatic Domain Model'; export SVG for the team wiki.
Who it's for
Built for any team that needs clear structure diagrams fast.
Design domain models
Sketch core entities, interfaces, and inheritance hierarchies to align teams before writing a single line of code.
Teach OOP and UML
Show class, member, and relationship basics with clear visuals that students can explore and edit themselves.
Contract-first API design
Model service interfaces, DTOs, and dependencies visually to guide implementation and keep contracts explicit.
Document system structure
Capture current-state and target-state class structures for stakeholder reviews and architecture decisions.
Templates
Start with professionally designed templates
Inheritance Hierarchy Class Diagram Template
Quickly map OOP inheritance chains - from abstract base classes to concrete implementations - using this ready-to-edit UML class diagram template.
UML Class Diagram Template
Start with a ready-to-edit e-commerce class diagram and visualize your object-oriented system design in minutes.
Object Oriented Design Template: UML Class Diagram
Model class hierarchies, interfaces, and relationships in a clean, professional class diagram built for OOP design.
Data Classification Framework Class Diagram Template
A ready-to-use UML class diagram template that models data assets, classification levels, ownership, access policies, retention rules, and audit logging in one structured view.
Classroom Management System Class Diagram Template
A structured UML class diagram that maps every key entity in a classroom management system — from teachers and students to assignments, grades, and attendance.
View All Templates
Browse the full library to find more templates tailored to your chart.
Why this beats manual drawing
Less busywork, more clarity.
Traditional diagramming tools
- ✗Manual box-and-line drawing is slow and error-prone
- ✗Constant re-alignment after every change
- ✗Hard to keep UML notation consistent
- ✗Full redraws required after scope changes
- ✗Clunky export and file-sharing workflows
AI-powered class diagram generator
- ✓Describe in plain text and get a diagram in seconds
- ✓Auto layout keeps spacing and alignment clean
- ✓Consistent UML stereotypes and visibility throughout
- ✓Edit once and the diagram updates automatically
- ✓One-click SVG/PNG export and instant share link
Class diagram generator FAQs
What is a class diagram generator?
A class diagram generator is a tool that creates UML class diagrams from text input or visual editing. It handles layout, notation, and relationships automatically so you can focus on your model rather than drawing boxes and lines by hand.
What is a UML class diagram?
A UML class diagram shows classes, their properties and methods, and the relationships between them such as inheritance, composition, and association. It is the standard format for documenting object-oriented domain models and software architecture.
How does the AI class diagram generator work?
Describe your domain in plain language or paste class definitions. The AI identifies classes, members, stereotypes, and relationships, then arranges them into a clean, readable diagram. You can refine every detail in the editor afterward.
Which relationship types does the online class diagram maker support?
Inheritance, composition, aggregation, association, dependency, realization, link, and dashed link are all supported. Add labels and cardinalities such as 1, 0..1, or 1..* to any relationship to match your domain exactly.
Can I set stereotypes, visibility, and method signatures?
Yes. Mark any class as interface, abstract, enumeration, or service. Control member visibility with public, private, protected, or package. You can also set return types and flag members as static or abstract.
Accessible by design
- ✓Readable fonts with adjustable size controls
- ✓Zoom and pan for users who need larger views
- ✓High-contrast lines and shapes for visual clarity
- ✓Distinct line styles to tell relationship types apart
- ✓Keyboard-friendly controls for essential editing
Privacy and control
- •Your diagrams are private until you share a link
- •You choose what to export or embed
- •Delete your work at any time
- •We do not sell your data
- •File uploads are optional and under your control
Create your class diagram now
Describe your model and get a ready-to-edit UML diagram in seconds.