Class Diagram Maker
Design UML class structures in minutes, not hours
Define classes, add attributes and methods, then connect them with inheritance, composition, and association relationships. Your class diagram renders instantly as you build.
Everything You Need in a Class Diagram Maker
Purpose-built for UML class modeling — from simple hierarchies to complex architectures
Full UML Class Support
Define classes with public, private, protected, and package visibility. Add attributes, methods, return types, and static or abstract modifiers to match standard UML notation precisely.
8 Relationship Types
Model inheritance, composition, aggregation, association, dependency, realization, link, and dashed link — covering every standard UML class relationship type.
Stereotypes for Precision
Mark classes as interface, abstract, enumeration, or service stereotypes so your diagrams communicate design intent at a glance.
Cardinality Labels
Annotate relationship lines with cardinality values (1, 0..1, 1..*, *) so multiplicity is always explicit and unambiguous in every class diagram.
AI-Powered Generation
Describe your system in plain English and the AI builds the class diagram — complete with classes, members, and relationships — ready to customize.
Zoom and Pan Navigation
Explore large class diagrams with smooth zoom and pan controls, keeping every detail readable even in complex multi-class designs.
Build Your Class Model Your Way
Type It In
Add classes, define attributes and methods, and set visibility modifiers directly in the editor.
Describe with AI
Tell the AI your system and it generates a full class diagram with classes, members, and relationships automatically.
Paste and Refine
Paste your class list or requirements and let the tool structure your UML diagram for you.
Upload Data File
Import structured data from CSV or Excel files to scaffold your class diagram quickly (Pro).
Share Your Class Diagrams Anywhere
Export PNG or SVG
Download crisp, high-resolution class diagrams for documents, slide decks, and technical specifications.
Share via Link
Generate a shareable link so teammates and reviewers can view your class diagram instantly.
Embed in Your Site
Add an interactive class diagram to your documentation or wiki with a simple embed code (Plus).
Drop Into Any Doc
Export and paste your class diagram into Notion, Confluence, Figma, or any documentation tool.
About This Class Diagram Maker
MakeCharts provides a free, browser-based class diagram maker built for developers, students, and architects. Create UML class diagrams with a clean visual editor, AI generation, and instant export — no installation or prior UML experience required.
- ✓Supports all core UML class diagram notation elements
- ✓8 relationship types with label and cardinality support
- ✓AI generation from plain-English system descriptions
- ✓Export to PNG and SVG for docs, slides, and wikis
- ✓Part of a 30+ chart and diagram library on MakeCharts
- ✓Free to use — no sign-up required to get started
Class Diagram Maker by the Numbers
How to Create a Class Diagram
From blank canvas to finished UML diagram in three simple steps
Add Your Classes
Click 'Add Class' to create a new class box. Enter the class name, choose an optional stereotype such as interface or abstract, then add attributes and methods with their types and visibility modifiers.
Create 'Animal' as an abstract class with a protected 'name' attribute and an abstract 'speak()' method returning void.
Define Relationships
Use the Relationships panel to connect classes. Select the relationship type — inheritance, composition, aggregation, association, or others — then set an optional label and cardinality value.
Add an inheritance relationship from 'Dog' to 'Animal', then a composition from 'Order' to 'OrderItem' with cardinality '1..*'.
Customize and Export
Set a chart title and adjust font size in Chart Settings. Enable zoom and pan for large diagrams. Then download as PNG or SVG, share a link, or embed the diagram directly in your docs.
Export your e-commerce class diagram as an SVG and paste it into your technical specification document.
Who Uses This Class Diagram Maker
From student assignments to enterprise architecture — class diagrams for every context
Object-Oriented Design
Plan and communicate class structures before writing code. Map inheritance hierarchies, define interfaces, and clarify responsibilities between classes early in the development cycle.
Teaching OOP Concepts
Create clear visual examples of object-oriented principles for lectures, assignments, and study materials. Students can build and submit class diagrams as part of software design coursework.
Architecture Documentation
Document the structural design of systems and services so engineering teams, new hires, and stakeholders all share the same mental model of how components relate.
API and SDK Documentation
Include class diagrams in developer documentation and SDK guides to show how classes, interfaces, and enumerations relate — making it far easier for developers to understand and adopt your API.
Class Diagram Maker vs. Traditional Diagramming Tools
Why developers and architects choose MakeCharts for UML class diagrams
Traditional Tools
- ✗Hours spent dragging boxes and drawing arrows manually
- ✗Steep learning curve for dedicated UML software
- ✗Expensive licenses for enterprise diagramming tools
- ✗No AI assistance — every class and member entered by hand
- ✗Painful to update when the design changes mid-project
- ✗Export options locked behind costly paid tiers
MakeCharts Class Diagram Maker
- ✓Describe your system and AI generates the diagram instantly
- ✓Intuitive editor — no prior UML tool experience required
- ✓Free tier covers full class diagram creation and export
- ✓8 relationship types with cardinality labels built in
- ✓Edit classes and relationships in seconds as your design evolves
- ✓Share via link, PNG, SVG, or embed code
Class Diagram Maker — Frequently Asked Questions
What is a class diagram?
A class diagram is a UML (Unified Modeling Language) structural diagram that shows the classes in a system, their attributes and methods, and the relationships between them. It is the foundation of object-oriented design and is widely used in software engineering to plan, document, and communicate system architecture.
Is this class diagram maker free?
Yes — creating and exporting class diagrams is free with no sign-up required. Free accounts also include limited AI credits to try AI-powered class diagram generation. Paid plans unlock more AI credits, SVG exports, embed codes, and file upload.
Can I generate a class diagram from a text description?
Yes. Use the AI-powered input to describe your system in plain English — for example, 'An e-commerce system with Product, Cart, Order, and User classes.' The AI generates a complete class diagram with classes, attributes, methods, and relationships. You can then edit and refine it as needed.
What relationship types does the class diagram tool support?
The tool supports all standard UML class diagram relationships: inheritance, composition, aggregation, association, dependency, realization, link, and dashed link. Each relationship supports an optional label and cardinality value such as 1, 0..1, 1..*, or *.
Can I add interfaces and abstract classes?
Yes. Each class supports stereotypes including interface, abstract, enumeration, and service. Individual members can be marked as abstract or static, and visibility can be set to public, private, protected, or package for each attribute and method.
Built for Every Team
- ✓Works for students, developers, architects, and technical writers
- ✓No UML experience required — the editor guides you step by step
- ✓Accessible on any device, from desktop workstations to tablets
- ✓Supports 12+ languages across the full application interface
- ✓Free tier covers full functionality with no time limit
- ✓Designed for solo creators and collaborative teams alike
Your Diagrams Stay Yours
- •Your class diagram data is used only to render your diagram
- •We do not sell or share your data with third parties
- •Diagrams are private by default — you control what is shared
- •Download or delete your work at any time
- •No tracking of individual diagram content for advertising purposes
Start Your Class Diagram Now
Free, no sign-up required. Your first class diagram is minutes away.