PlantUML Viewer
A free, in-browser PlantUML viewer for entity and class diagrams. Paste your @startuml … @enduml block and see it rendered as an interactive diagram — no Java, no PlantUML server, nothing uploaded.
How it works
- Copy your PlantUML
@startuml … @endumlblock. - Paste it into the viewer — PlantUML is auto-detected.
- Each
entity/classbecomes a table; relationship lines become relations. - Drag to arrange, then export PNG/SVG or convert to Mermaid/DBML.
Example
Paste PlantUML like this:
@startuml
entity users {
* id : int
email : varchar
}
entity orders {
* id : int
user_id : int
}
users ||--o{ orders
@enduml
…and the viewer draws two tables with a relation from orders → users. Try it with your own →
Why use it
- Private: everything runs in your browser — nothing is uploaded or stored on a server.
- No server, no Java — renders instantly in the browser, unlike a PlantUML render pipeline.
- Interactive: drag tables, auto-arrange, hide noise, add notes, and manually link columns.
- Export a high-res PNG, vector SVG, or the schema as Mermaid / DBML / PlantUML code.
- Free & open source — no account, no sign-up.
FAQ
Do I need a PlantUML server or Java to view a diagram?
No — paste the PlantUML text and it renders directly in your browser as an interactive diagram you can edit and export.
Which PlantUML diagrams can I view?
Entity-relationship and class diagrams: entity / class blocks with fields, plus relationship connectors like ||--o{.
Is my schema uploaded anywhere?
No. Everything runs locally in your browser — your schema is never uploaded to or stored on any server.
Can I export the diagram?
Yes — export a high-resolution PNG or vector SVG, copy the schema as Mermaid, DBML or PlantUML, or share a link that encodes the whole diagram in the URL.
Is it free?
Yes. It is completely free and open source, with no account or sign-up required.