PlantUML source editor
Edit diagram source directly when exact syntax and control matter.
PlantUML source and preview together
Online PlantUML editor for collaborative diagramming
Write or paste PlantUML, collaborate on the source, render a visual preview, explore templates, and download the result from one browser room.
Open the PlantUML editor
No installation · Start free
@startuml
Live preview
actor User
User -> API: Sign in
API --> User: Session
Changes and reactions update live
Useful by design
Everything you need in one shared room
Rendered preview
Turn valid PlantUML source into a visual diagram beside the editor.
Real-time source collaboration
Work on the same diagram source with other room participants.
Built-in examples
Start from sequence, class, activity, ER, Gantt, mind map and other templates.
AI-assisted refinement
Ask AI to generate or modify PlantUML, then inspect and edit the returned source.
PNG download
Download the successfully rendered diagram as an image.
Start in seconds
How it works
- Open DiagramStart the room directly in the Diagram workspace.
- Write or choose an examplePaste PlantUML source or start from one of the included templates.
- Render and correctReview the preview and fix any PlantUML syntax errors in the source.
- Share or downloadInvite collaborators or download the rendered image.
Made for real work
Ways to use it
Sequence diagrams
Document interactions between people, services and APIs.
Architecture diagrams
Describe components and dependencies as versionable text.
Database modeling
Draft entity relationships using PlantUML syntax.
Technical documentation
Keep diagram source beside project notes and files.
Questions and answers
Frequently asked questions
Do I need to install PlantUML?
No. The editor and rendering workflow run through the LiveShareIt web room.
Can I edit the generated source?
Yes. AI and templates produce normal PlantUML source that remains editable.
What happens when the syntax is invalid?
The preview cannot render until the source is corrected. The source remains available for editing.
Can collaborators edit simultaneously?
Yes, when room access permits editing, PlantUML source is synchronized between participants.
Ready to create a shared room?
Open the tool now, then invite others with one link.
Open the PlantUML editor Or return to the LiveShareIt home page