Object Diagram Maker

Build UML class diagrams with AI in minutes

Design professional object and class diagrams with classes, attributes, methods, and relationships. Our AI-powered object diagram maker handles the structure so you can focus on your system design.

Describe your object model or paste existing class names to get started instantly.

Everything an Object Diagram Maker Should Do

Purpose-built for UML class and object modeling - not a generic shape editor

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Full UML Relationship Support

Model inheritance, composition, aggregation, association, dependency, and realization. Every core UML relationship type is supported with proper notation.

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Rich Member Editor

Define attributes and methods with types, visibility (public, private, protected, package), and modifiers like static and abstract.

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Class Stereotypes

Tag classes as Interface, Abstract, Enumeration, or Service to communicate intent clearly in every object diagram.

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AI-Generated Diagrams

Describe your system in plain language and get a complete class diagram with realistic classes and relationships in seconds.

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Cardinality Labels

Specify cardinality (1, 0..1, 1..*, *) on any relationship to express multiplicity clearly and precisely.

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Zoom and Pan

Navigate large, complex object diagrams comfortably with built-in zoom and pan controls for detailed review.

Bring Your Object Model to Life

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Describe in plain language

Type a description of your system and the AI generates classes, members, and relationships automatically.

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Define classes manually

Add classes one by one with full control over attributes, methods, visibility, and stereotypes.

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Model existing code

Reverse-engineer your codebase by describing your existing classes and let the tool map the structure visually.

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Paste class names

Start with a list of class names and the AI infers plausible relationships and member structures for you.

Share Your Diagrams Anywhere

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Export as PNG or SVG

Download crisp, high-resolution diagrams ready for documentation, presentations, or technical specs.

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Share with a link

Generate a shareable URL so teammates and stakeholders can view your object diagram instantly.

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Embed in your site

Drop your class diagram directly into wikis, dev portals, or documentation sites with a simple embed code.

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Export for slides

Paste your diagram into design reviews, architecture proposals, or onboarding decks in seconds.

About This Object Diagram Maker

MakeCharts is a free online chart and diagram tool used by developers, educators, and teams worldwide. The object diagram maker is part of a suite of 30+ visualization types. It was built to make UML accessible - fast, visual, and AI-assisted.

  • Supports all 8 core UML relationship types
  • AI generation from plain-language descriptions
  • Full member editor with types, visibility, and modifiers
  • Instant PNG and SVG export
  • Shareable links and embed codes
  • Free with no sign-up required

Object Diagram Maker by the Numbers

Time to first diagram
<2 min
Relationship types
8 types
Visibility modifiers
4 levels
Supported stereotypes
5 types
Languages supported
12+

How the Object Diagram Maker Works

From idea to polished UML diagram in three simple steps

1

Describe or Define Your Classes

Type a plain-language description of your system or manually add classes with names and stereotypes.

'Online library with Book, Member, and Loan classes - Book has a composition with Chapter'

2

Add Members and Relationships

Define attributes and methods with visibility modifiers, then connect classes with the appropriate relationship type and cardinality.

Add a private 'isbn: String' attribute to Book, then link Book to Loan with a '1..*' association

3

Export and Share

Download your object diagram as PNG or SVG, share via link, or embed it in your documentation.

Export as SVG for your architecture wiki or share the link in your next design review

Who Uses This Object Diagram Maker

From solo developers to enterprise architecture teams

Software Development

System Architecture and Design

Visualize object-oriented designs before writing code, making architectural decisions clearer and easier to review with the team.

Domain model diagrams
Microservice class structures
API response object layouts
Refactoring blueprints
Education

Teaching Object-Oriented Concepts

Create clear, accurate class diagrams for lectures, assignments, and textbooks that illustrate OOP principles visually.

Inheritance hierarchy examples
Design pattern illustrations
Student project templates
Exam question diagrams
Technical Documentation

Developer Guides and API Docs

Embed object diagrams directly in README files, wikis, and API references so developers understand data structures at a glance.

SDK class references
Database entity structures
Framework extension points
Onboarding documentation
Product and Engineering

Feature Planning and Code Reviews

Sketch proposed class structures during planning sessions and include object diagrams in pull request descriptions for clarity.

Feature RFC diagrams
Code review illustrations
Sprint planning visuals
Tech spec attachments

Object Diagram Maker vs. Traditional UML Tools

Why teams switch from heavyweight UML software to MakeCharts

Traditional UML Tools

  • Steep learning curve with complex interfaces
  • Expensive licenses for full UML feature sets
  • Manual dragging and connecting of every element
  • Slow exports and compatibility issues
  • No AI assistance for generating initial structures
  • Hard to share without installing the same software

MakeCharts Object Diagram Maker

  • Intuitive class editor with no learning curve
  • Free to use with all core UML relationship types
  • AI generates complete diagrams from a text description
  • Instant PNG and SVG export, shareable links included
  • Refine any diagram with AI chat in plain language
  • Share via link or embed - no installs required

Frequently Asked Questions

What is an object diagram maker?

An object diagram maker is a tool for creating UML diagrams that show the structure of object-oriented systems. It lets you define classes with their attributes and methods, then connect them with relationships like inheritance, composition, and association. MakeCharts makes this process fast and visual.

Can I use this as a class diagram maker too?

Yes. MakeCharts uses UML class diagram notation, so it works equally well as a class diagram maker and an object diagram maker. You can define class structures with full member details or create instance-level object diagrams depending on your needs.

What relationship types are supported in the object diagram maker?

The tool supports all core UML relationship types: inheritance, composition, aggregation, association, dependency, realization, link, and dashed link. Each relationship can have a label and cardinality notation like 1, 0..1, 1..*, or *.

How does the AI class diagram generation work?

Describe your system in plain language - for example, 'an e-commerce platform with customers, orders, and products.' The AI interprets your description and generates a class diagram with appropriate classes, members, and relationships. You can then refine any part of the output manually.

Is this object diagram tool free?

Yes, the core object diagram maker is completely free with no account required. You get access to all class types, relationship types, and export options. Free AI credits are also included so you can try AI-generated diagrams right away.

Built for Every Developer and Designer

  • Works in 12+ languages so global teams can collaborate without friction
  • No installation or account required to start building object diagrams
  • Beginner-friendly controls with expert-level UML accuracy
  • Optimized for desktop and tablet screens to fit your workflow
  • AI assistance lowers the barrier for teams new to UML modeling
  • Free tier ensures solo developers and students get full access

Your Diagrams Stay Yours

  • Your class diagram data is used only to render your diagram
  • We do not sell or share your object model data with third parties
  • You control sharing - diagrams are private by default
  • Download or delete your work at any time
  • No tracking of the content inside your diagrams

Start Your Object Diagram Now

No sign-up. No install. Just describe your system and your class diagram is ready in seconds.

All 8 UML relationship types
AI-powered class generation
Free PNG and SVG export
Shareable diagram links
No account required