PlantUML to ER Diagram
Paste a PlantUML entity or class diagram and turn it into a fully interactive ER diagram — drag tables, auto-arrange, and export — no Java or PlantUML server required.
Open the diagram tool →
At a glance
- What it is
- SQL to ER Diagram is a free, open-source browser tool that turns a PlantUML entity or class diagram into an interactive entity-relationship (ER) diagram.
- Input
- A PlantUML entity or class diagram: an
@startuml … @endumlblock. - Output
- An interactive ER diagram you can rearrange, then export as PNG, SVG, Mermaid, DBML or PlantUML, or share as a link.
- Cost
- Free. MIT-licensed open source. No account or signup.
- Privacy
- Runs entirely in your browser. The schema is never uploaded, and share links carry the diagram in the URL fragment, which is not sent to a server.
- Limits
- It never connects to your database itself: you paste schema text, or run one read-only catalog query in your own client and paste the result. There are no accounts, so there is no real-time multi-user editing; diagrams are kept in your browser, as a saved file, or as a share link. Layout stays smooth at around 300 tables.
How it works
- Copy your PlantUML
@startuml … @endumlblock (entity or class diagram). - Paste it into the editor — PlantUML is auto-detected.
- Each
entity/classbecomes a table; relationship lines become relations. - Arrange, hide tables, then export PNG/SVG or convert to Mermaid/DBML.
Example
PlantUML like this:
@startuml
entity users {
* id : int
email : varchar
}
entity orders {
* id : int
user_id : int
}
users ||--o{ orders
@enduml
…renders two tables with a relation from orders → users. Try it with your own →
Guide
PlantUML's entity and class diagrams have been the default way to put an ERD in a wiki for a decade — but rendering them requires the PlantUML jar, a Java runtime, or a round-trip to the public PlantUML server. This page renders them client-side: paste your @startuml … @enduml block and get an interactive canvas instead of a fixed image.
What's supported
entity users { * id : int … }blocks — the*mandatory marker becomes a NOT-NULL badge, types carry over.- Class-diagram style
class users { id : int }blocks (common in older diagrams). - Relationship connectors with IE crow's-foot notation:
users ||--o{ orders, plus--plain associations.
Skinparam, theme and hide circle directives are skipped — they're render hints, not schema. The point isn't to replace PlantUML for every diagram type; it's that when the diagram is about your database, you should be able to drag a table two inches to the left without re-running a render pipeline. Export SVG/PNG when you're happy, or convert to Mermaid/DBML to move the schema into a different toolchain.
Why use it
- Private: everything runs in your browser — nothing is uploaded or stored on a server.
- No server needed — 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?
No — paste the PlantUML text and it renders directly in your browser as an interactive diagram you can edit and export.
Which PlantUML diagrams work?
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.
Is it free?
Yes. It is completely free and open source, with no account or sign-up required.