Online UML Diagram Tool

Design better software with better UML tools.

The Easy Choice for Software Development Teams

Easy to Use

SmartDraw has templates for every type of UML diagram you might need to visualize your software architecture from class and use case diagrams to activity diagrams, and more. You can easily build any UML diagram by drawing a line and choosing a new symbol from the auto-prompt menu of common symbols for your chosen diagram type. SmartDraw's UML maker also have context sensitive tools to help you change line and arrowhead types to indicate relationships and add symbols to indicate multiplicity.

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Easy to Generate Automatically

SmartDraw can generate a visual representation of your code from your repository on GitHub or your local computer. You can create a UML class diagram without any drawing at all. Visualize your classes and their properties automatically whether you write C#, C, Java, JavaScript, Ruby or Python.

Easy to Work With Other Apps

SmartDraw is easy to work with no matter what other apps you use. You can add UML diagrams to:

  • Microsoft Office®
    • Word®
    • PowerPoint®
    • Excel®
  • Microsoft Teams®
  • Google Workspace
    • Google Docs
    • Google Sheets
  • Atlassian apps
    • Confluence
    • Jira

Easy to Save to Your Existing Storage Solution

SmartDraw works hand in glove with most file storage systems. You can save your UML diagrams directly to:

  • SharePoint®
  • OneDrive®
  • Google Drive
  • DropBox®
  • Box®

There is no need to create a parallel set of common folders and permissions, SmartDraw can just save files directly into your existing set up.

Easy to Share

Share your UML diagram with anyone, even if they don't own a copy of SmartDraw, with a link. You can also easily export any diagram as a PDF or common image formats like PNG or SVG.

Easy to Share

Easy to Get Help

Have a question? Chat or email us. SmartDraw support is in-house and free!

Easy to Get Help

Easy Collaboration

UML diagrams are an essential part of both the documentation and design process of any software project. Make sure everyone on your team shares your vision and has a chance to offer input.

SmartDraw lets you share diagrams, add comments, and work together to build better products.

You can also easily collaborate on designs in Microsoft Teams®, Slack or Confluence.

Collaboration with UML

Our UML Diagram Tool Features

  • Standards compliant UML shapes
  • UML 2.0 templates
  • Built-in standard arrow notations
  • Generate class diagrams automatically
  • Connect to GitHub
  • Contextual comments
  • Version history
  • Build custom libraries
  • Build custom shapes
  • Export as PDF, PNG, or SVG
  • Works with Google Workspace
  • Works with with Microsoft Office®
  • Works with Microsoft Teams®
  • Works with 3rd party storage providers

How to Generate a Class Diagram from Data

Step 1

Connect Your Code Repository

You can point SmartDraw at your repository or load your source code and choose which files you want to include in your diagram. Learn more about SmartDraw's class diagram builder.

Step 2

Build and Edit Your Diagram

Click "Build Diagram" to create your class diagram. The class diagram generated is fully editable. You can add new shapes to it or modify its properties. Clicking on the "info" icon will show you the description for each method and the the hyperlink links to the specific line in the sourcecode.

How Create a UML Diagram Online

Step 1

Pick a Template

SmartDraw has every type of UML diagram your team needs to design and document systems. Select the type of visual you need, whether structural or behavioral, and all the relevant tools and symbols will be docked next to your work area.

Step 2

Add Shapes

Drag and drop your first symbol to the drawing. Once you already have a shape, you can add new ones by drawing a line and choosing a symbol from the auto-prompt that appears.

This menu is pre-populated with the most common symbols for the selected diagram type. The options will change over time to symbols you use, so you'll always have what you need at your fingertips.

Step 3

Define Relationships

Most UML diagrams involve connecting one or more shapes to each other using lines with special symbols or arrowheads to indicate relationships like aggregation, dependency, inheritence, composition, and association for classes and interface type for components. SmartDraw has a context sensitive line style menu for the type of UML diagram you're making to make defining relationships easy.

Step 4

Define Multiplicity

Some UML diagrams like class diagrams often use a multiplicity notation to indicate the number of instances of one class linked to one instance of the other class. SmartDraw makes adding multiplicity easy by another context sensitive meny that lets you define them in just a few clicks.

Step 5

Add Text

Make sure you add labels to all your classes, use cases, and actors at the level of detail appropriate for your audience. Not all stakeholders will need the visual to be super technical to be able to give feedback about the system.

What is a UML Diagram?

UML stands for Unified Modeling Language. The purpose of a UML diagram is to create a visual model of a software system. UML diagrams can show the structure of a system and its components like classes, packages, and objects. They can also show how the system behaves, acts, and communicates. There are 13 different types of UML diagrams supported by the UML 2.0 standard. They are:

Structural UML diagrams

  • Class diagram
  • Package diagram
  • Object diagram
  • Component diagram
  • Composite structure diagram
  • Deployment diagram

Behavioral UML diagrams

  • Activity diagram
  • Sequence diagram
  • Use case diagram
  • State diagram
  • Communication diagram
  • Interaction overview diagram
  • Timing diagram

Frequently Asked Questions (FAQ) About UML

What are UML diagram types?

There are 13 types of UML diagrams in UML 2.0 divided into two categories: structural and behavioral. Learn more

What is a class diagram?

Class diagrams are the backbone of almost every object-oriented method of software development. A class diagram describes the static structure of a system and how classes are related to one another. Learn more

What is a use case diagram?

A use case diagram is a dynamic or behavior diagram in UML. Use case diagrams model the functionality of a system using actors and use cases. Use cases are a set of actions, services, and functions that the system needs to perform. Learn more

Why make UML diagrams?

Any time you want to create a complex system with many team members and collaborators, you'll need a solid foundation of planning and design so everyone can agree on the structure and behavior of the system. This will help avoid miscommunication and save time as the project progresses.

UML Symbols

The 13 different types of UML diagram each have a slightly different symbol set. Class diagrams are perhaps one of the most common UML diagrams used and class diagram symbols center around defining attributes of a class. For example, there are symbols for active classes and interfaces. A class symbol can also be divided to show a class's operations, attributes, and responsibilities. Another common UML diagram for use cases will have unique symbols for actors and use cases. SmartDraw will include all the relevant UML symbols based on the type of UML template you select.

Lines are also important symbols to denote relationships between components. Generalization and Inheritance are denoted with empty arrowheads. Composition is shown with a filled in diamond. Aggregation is shown with an empty diamond. Dependencies are marked with a dashed line with an arrow.

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3M logo
Amazon logo
AT&T logo
Cisco logo
Honeywell logo
Intel logo
Johnson and Johnson logo
Mariott logo
Abbott Labs logo
Motorola logo
Northrop Grumman logo
Oracle logo
Pfizer logo
Thermo Fisher Scientific logo
Verizon logo
Wells Fargo logo

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