PlantUML deprecation notice

[davidjgraph]

We'll be removing support for PlantUML on app.diagrams.net on 30st June 2026 (for Confluence and Jira Cloud draw.io customers the date is November 30th 2028). There are a number of factors in this decision:

• Mermaid.js is a very good alternative that we've supported for several years, is natively supported on platforms like github and gitlab, and we have better support for mermaid than we do for plant.
• PlantUML requires a security review on every update and the project itself doesn't seem to conduct security reviews. Though, note we have a sandbox implementation that maintains complete full per invocation isolation.
• PlantUML is server based, draw.io is a client-side architecture, Mermaid.js is a far better fit.
• The PlantUML project is very unfocused. It add all kinds of random software that doesn't belong, like a sudoku generator and the oregon trail text adventure. This adds time stripping the excess out from the build.

The PlantUML text will remain in the diagram and be accessible if you wish to port it to another tool. You won't lose PlantUML generated images, or the underlying data.

There are alternative PlantUML specific solutions available online, like https://www.planttext.com/ or https://plantuml-editor.kkeisuke.com/.

There's also https://github.com/doubleSlashde/plantuml2drawio and https://github.com/rglaue/plantuml_to_drawio.

For Confluence Cloud there is a well established solution, https://marketplace.atlassian.com/apps/1215115/plantuml-diagrams-for-confluence?hosting=cloud&tab=overview.

[piotr-albertin]

Does it mean that mermain.js will be available within the draw.io, both desktop app and integration with Confluence?

[davidjgraph]

yes, mermaid.js is already available across all draw.io platforms.

[jldupont-soralink]

Currently, there is no way (that I know of at least) of editing the generated diagram using the original mermaid text. Is there any plans to support this ?

[davidjgraph]

You select image instead of diagram in the mermaid dialog pull down.

[jldupont-soralink]

@davidjgraph Thank you so much !

[siddharthgoel88]

I was scared what would happen to my zillions of PlantUML diagrams that I have inserted in Confluence via Draw.io . Thankfully the support is still there till 2028 for Confluence 👍

[bakafox]

Great decision. Let PU finally rest in peace, it should've been dead years ago...

[dominikwenning]

Is there any way to get back the mermaid.js code after editing the diagram?

[davidjgraph]

#5074 (reply in thread)

[dominikwenning]

@davidjgraph Thanks, but this is how I import the code right? I mean how I can get it back after I was editing it. Like an export of the mermaid code.

[davidjgraph]

We don't have draw.io export to mermaid, but we don't have export to PlantUML either.

[ToadCodeGitHub]

@davidjgraph I have a local server running plantUML and draw.io v27.0.0 and it does not have plantuml support. What version of draw.io should I be using?

[ToadCodeGitHub]

sorry typeO v27.0.9

[arnaudroques]

Hi David, it's been a long time :-)

Thank you for your message and for your transparency.

We fully understand and respect your decision. We understand that the main technical reason is the server-side nature of PlantUML, which is fundamentally different from draw.io's client-side architecture. Mermaid.js is indeed a great alternative and is better aligned with your technical approach, even though (in our admittedly biased opinion!) PlantUML remains the more feature-rich option.

Regarding your remark about the inclusion of unrelated tools (such as the sudoku generator or Oregon Trail text adventure): if this is a significant pain point, we would be happy to consider providing and maintaining a streamlined, professional build of PlantUML containing only the core diagram generation features, without these experimental or fun additions. However, we fully recognize that the core architectural issue (server-side vs. client-side) is likely the primary factor behind your decision.

Finally, we would like to sincerely thank the draw.io team for having supported PlantUML for so many years, and for providing users with access to our diagramming technology. We appreciate the collaboration and remain available for any questions or further technical discussions, if helpful.

Best regards,
The PlantUML team

[davidjgraph]

Hey Arnaud, j'espère que tu vas bien. And thank you for providing the functionality for so long.

In terms of stripping stuff out, ultimately, it's free and it's your project. You don't owe us or anyone else anything. and my sudoku has improved.

It's certainly true that there's a large base for Plant that still uses it. A PlantUML to draw.io JS convertor would give you client-side rendering, though the import stuff would be hard...

[arnaudroques]

It's certainly true that there's a large base for Plant that still uses it. A PlantUML to draw.io JS convertor would give you client-side rendering, though the import stuff would be hard...

You’re absolutely right. For now, unfortunately, we don’t have anything truly client-side.

We experimented with two different approaches, but neither is really usable yet:

• A partial re-implementation in Haxe (https://haxe.org/), targeting only a small subset of PlantUML (specifically, MindMap diagrams).
  Haxe can generate JavaScript, so this actually produced a working pure client-side demo: https://plantuml.com/en/haxe-demo-javascript.
  However, porting the entire codebase from Java to Haxe would be a huge and time-consuming project.

• Running Java in the browser using CheerpJ (https://cheerpj.com/), which allows Java programs to run natively as WebAssembly.
  This is actually a really impressive technology.
  The demo page is here https://plantuml.github.io/plantuml.js/ but unfortunately, the performance is not sufficient for production use. The application startup literally takes several minutes, making it impractical for real scenarios.

For now, both efforts are on hold. Maybe, as generative AI and related tools improve, a new solution will eventually emerge.
But I wouldn’t hold my breath :-)

Maybe I’ll write to you again in 5 or 10 years. In the meantime, thanks again for everything!

[rehevkor5]

Both the PlantUML and Mermaid.js support suffer from the same core issues:

1. Can't see a preview rendering of the diagram, so you have no idea what it will look like / no meaningful editing. So, you end up having to use some external editor instead.
2. Can't edit the diagram after you insert it, and can't really recover the original text (unless you wanna copy it out of a JSON property)

Also, Mermaid is missing basic stuff like left-aligning the content of a text note (important to make things readable such as lists).

[davidjgraph]

2. Yes, you can, read the comments above.

[vgallegob]

Well, that is unfortunate. I really enjoy plantuml.

I think it's much more expressive for large technical diagrams.

draw.io was excelent for keeping a "book" of diagrams...

why not allow calling plantuml server? they have a public api

it's a petty.. I have soo many diagrams

[davidjgraph]

Our CSP would block replies from an unknown server.

[vgallegob]

You can call plantuml from the backend. Like a proxy. More over, you could allow me to set a custom plantuml server url optionally.

Win win. Secure, simpler, faster.

[davidjgraph]

This is an SOC 2 Type II grade system, we cannot call out to servers that we do not control or are not SOC 2 Type II themselves and we have a commercial contract in place with them.

[vgallegob]

Oh ok, my bad.

What if you run your own plantuml server with a docker image?

I don't know, I'm just brainstorming at this point. 😕

[davidjgraph]

PlantUML doesn't undergo any security reviews, a docker image isn't secure enough. Our current system maintains full invocation isolation. We just don't want to maintain it forever.

[davidjgraph]

We've moved the dates out 6 months to give users more time to adjust.

[khurtwilliams]

The deprecation of PlantUML in draw.io is more than an inconvenience — it may be a deal-breaker for enterprise users.

My team has invested in PlantUML for architecture and security diagrams. With this change, we’re left with Mermaid, which is not a one-to-one replacement and throws cryptic parse errors on even simple snippets. I don’t know Mermaid, and our teams shouldn’t have to relearn an entirely different DSL just to keep existing diagrams functional.

This puts me in a position where I now have to recommend that my employer evaluate alternative diagramming tools. If draw.io can’t maintain PlantUML support or provide a reliable migration path, we’ll be forced to move.

Please reconsider the decision, or at least:
• Keep PlantUML support available as an option,
• Provide a robust conversion tool for existing PlantUML diagrams,
• Or publish detailed documentation of what Mermaid features are supported and how they differ.

Without one of these, draw.io is effectively breaking workflows for long-time users and organisations that standardised on PlantUML.

[davidjgraph]

This is using draw.io within confluence cloud?