Create a PlantUML object diagram online to capture specific instances, current attribute values, and the links between them, then preview and export PNG or SVG.
Start with the Object Diagram template, edit the PlantUML source, and preview the result live.
Use this focused object diagram tool for quick previews and exports. Open the full editor for AI generation, syntax repair, sharing, and saved projects.
Model specific object instances, current attribute values, links, relationship labels, and a system snapshot at one point in time in an editable PlantUML workspace with live preview and PNG or SVG export.
Start from valid PlantUML source designed for a practical object diagram.
See the rendered diagram update as you edit the PlantUML source.
Learn the syntax and modeling choices used for debugging runtime state, documenting test fixtures, reviewing concrete business scenarios, and explaining worked examples.
Download a shareable PNG or scalable SVG from the same source.
Create and preview PlantUML without installing Java, Graphviz, or an IDE extension.
Move to the full editor for AI generation, repair, sharing, and saved projects.
Use the built-in template to create a object diagram for debugging runtime state, documenting test fixtures, reviewing concrete business scenarios, and explaining worked examples.
Choose one moment or business scenario for the snapshot, such as an order immediately after payment.
List the object instances that exist at that moment and name each instance clearly.
Add only the attribute values needed to explain the scenario.
Connect the instances and label each link with its business meaning.
Check the live preview, then export the object diagram as PNG or SVG.
Learn the core syntax and modeling decisions behind a useful object diagram, then apply them directly in the online editor above.
Use the object keyword for a concrete instance. A label such as orderA001 : Order identifies both the instance and its type. Put current values inside braces so the diagram records what is true in this scenario, not every field the class could contain.
object "orderA001 : Order" as order {
number = "A-001"
status = "Paid"
total = 299.00
}Connect instances with a solid or directed relation and add a short label after a colon. Labels such as places or paid by explain the business meaning of the link. Add cardinality only when it helps readers understand this specific snapshot.
customer -- order : places
order -- payment : paid byUse an object diagram when the question is which instances exist now, what values they hold, and how they are linked. Use a class diagram when the question is which types, attributes, methods, and type relationships define the system.
Choose one point in time and include only the objects and values needed to explain it. If the diagram mixes several lifecycle stages or becomes crowded with unrelated instances, split it into separate snapshots that each answer one review or debugging question.
The editable example demonstrates a practical object diagram. Change the source, check the live preview, and export the version you need.
@startuml
title Paid order snapshot
object "alice : Customer" as customer {
id = "C-1042"
name = "Alice"
}
object "orderA001 : Order" as order {
number = "A-001"
status = "Paid"
total = 299.00
}
object "paymentP01 : Payment" as payment {
id = "P-01"
status = "Captured"
amount = 299.00
}
customer -- order : places
order -- payment : paid by
@endumlUse these related tools when you need a different export format or a full PlantUML editing workflow.
Browse the complete OnUML matrix of online PlantUML tools and converters.
View all PlantUML toolsUse the general editor when you want to switch freely between diagram types.
Open the general editorCreate and export a focused class diagram with a built-in template.
Create a class diagramPlantUML keeps object diagrams in reviewable text, making them easier to update, version, reuse, and export as the design changes.
Open directly into a Object Diagram template instead of adapting an unrelated example.
Store the diagram as readable text that works well in documentation and version control.
Check structure, labels, and relationships before exporting the rendered diagram.
It is a browser-based editor that starts with a Object Diagram template and lets you edit PlantUML source, preview the rendered diagram, and export PNG or SVG without local setup.
Use it to model specific object instances, current attribute values, links, relationship labels, and a system snapshot at one point in time. Common uses include debugging runtime state, documenting test fixtures, reviewing concrete business scenarios, and explaining worked examples.
A class diagram describes reusable types and their structure. An object diagram shows concrete instances, their current values, and their links at one point in time.
No. Include only the values needed to explain the scenario, test case, or runtime state. Omitting unrelated fields keeps the snapshot easier to review.
Yes. Preview the diagram, then download PNG for slides and quick sharing or SVG for scalable documentation and web use.
No. The online tool uses a server-backed preview, so you can edit and render the diagram directly in the browser.
Open the full OnUML editor for AI generation, syntax repair, sharing, saved projects, and multi-format diagram workflows.