Components and Boundaries
Represent modules or services with component declarations or bracket notation. Group them inside package, node, cloud, or rectangle blocks when a system, team, runtime, or trust boundary matters.
PlantUML Component Diagram Online
Create a PlantUML component diagram online, map services and dependencies, preview the architecture, and export PNG or SVG.
PlantUML Component Diagram Online Editor
Start with the Component Diagram template, edit the PlantUML source, and preview the result live.
Use this focused component diagram tool for quick previews and exports. Open the full editor for AI generation, syntax repair, sharing, and saved projects.
Diagram preview
Create a PlantUML Component Diagram Online
Model components, services, interfaces, ports, databases, packages, dependencies, and architectural boundaries in an editable PlantUML workspace with live preview and PNG or SVG export.
Built-in Component Diagram template
Start from valid PlantUML source designed for a practical component diagram.
Live diagram preview
See the rendered diagram update as you edit the PlantUML source.
Focused component diagram guidance
Learn the syntax and modeling choices used for software architecture, microservice maps, module dependencies, integration documentation, and technical design reviews.
PNG and SVG export
Download a shareable PNG or scalable SVG from the same source.
No local setup
Create and preview PlantUML without installing Java, Graphviz, or an IDE extension.
Continue in OnUML
Move to the full editor for AI generation, repair, sharing, and saved projects.
How to Create a PlantUML Component Diagram
Use the built-in template to create a component diagram for software architecture, microservice maps, module dependencies, integration documentation, and technical design reviews.
- 01
Start with the built-in Component Diagram template.
- 02
Replace the sample components with deployable services or logical modules.
- 03
Group related components inside packages or system boundaries.
- 04
Connect dependencies and label the protocols or responsibilities they represent.
- 05
Preview and export the component diagram as PNG or SVG.
PlantUML Component Diagram Syntax and Use Cases
Learn the core syntax and modeling decisions behind a useful component diagram, then apply them directly in the online editor above.
Interfaces and Dependencies
Use arrows to show which component depends on another. Label a relationship with a protocol, event, API, or responsibility so the connection communicates more than simple proximity.
[Web App] --> [API Gateway] : HTTPS
[API Gateway] --> [Order Service] : RESTDatabases and External Systems
Combine components with general deployment elements such as database, queue, cloud, and node when infrastructure or external dependencies belong in the same architecture view. This makes ownership and operational boundaries easier to scan.
Choosing the Right Level of Detail
Keep one component diagram at one architectural level. A landscape view should show major systems; a service-level view can show modules and adapters. Split the model when every internal class begins appearing as a component.
PlantUML Component Diagram Example
The editable example demonstrates a practical component diagram. Change the source, check the live preview, and export the version you need.
@startuml
package "Web Application" {
[Frontend] as FE
[API Gateway] as GW
[Auth Service] as Auth
[Order Service] as Order
}
database "Database" as DB
FE --> GW : HTTPS
GW --> Auth : validate token
GW --> Order : route request
Order --> DB : read / write
@endumlRelated PlantUML Tools
Use these related tools when you need a different export format or a full PlantUML editing workflow.
PlantUML Tools
Browse the complete OnUML matrix of online PlantUML tools and converters.
View all PlantUML toolsPlantUML Online Editor
Use the general editor when you want to switch freely between diagram types.
Open the general editorPlantUML Sequence Diagram Online
Create and export a focused sequence diagram with a built-in template.
Create a sequence diagramWhy Use PlantUML for Component Diagrams
PlantUML keeps component diagrams in reviewable text, making them easier to update, version, reuse, and export as the design changes.
Start from the right diagram type
Open directly into a Component Diagram template instead of adapting an unrelated example.
Keep the model reviewable
Store the diagram as readable text that works well in documentation and version control.
Preview before sharing
Check structure, labels, and relationships before exporting the rendered diagram.
Frequently Asked Questions
What is a PlantUML component diagram online tool?
It is a browser-based editor that starts with a Component Diagram template and lets you edit PlantUML source, preview the rendered diagram, and export PNG or SVG without local setup.
What can I model in a component diagram?
Use it to model components, services, interfaces, ports, databases, packages, dependencies, and architectural boundaries. Common uses include software architecture, microservice maps, module dependencies, integration documentation, and technical design reviews.
What should a component represent?
A component should represent a replaceable software unit with a clear responsibility, such as a service, module, library, adapter, or frontend application.
Can PlantUML component diagrams show databases and queues?
Yes. PlantUML components can be combined with deployment elements such as database, queue, cloud, and node, then connected and labeled with the relevant protocol or data flow.
Can I export the component diagram as PNG or SVG?
Yes. Preview the diagram, then download PNG for slides and quick sharing or SVG for scalable documentation and web use.
Do I need to install PlantUML, Java, or Graphviz?
No. The online tool uses a server-backed preview, so you can edit and render the diagram directly in the browser.
Need AI-Assisted Diagram Editing?
Open the full OnUML editor for AI generation, syntax repair, sharing, saved projects, and multi-format diagram workflows.