Archgram vs PlantUML

PlantUML is a mature, widely used text language for UML with a large ecosystem of plugins and libraries, and it is a good fit for build pipelines. Archgram is a browser workspace for several notations. It edits PlantUML with a live preview and a form, converts flow, sequence, class and ER diagrams to and from other formats, drafts diagrams with AI and syncs them to Git. It does not aim to cover every PlantUML diagram type.

	Archgram	PlantUML
Setup	Runs in the browser	Typically a local install or a server, plus a rendering runtime
Notations	Mermaid, D2, PlantUML, Draw.io, Excalidraw	PlantUML
Coverage of UML	Focused on architecture diagrams; not every PlantUML type is drawn	Very broad
AI drafting	Built in, with your own AI key if you prefer	Not a core feature

Choose PlantUML if

You need the full breadth of UML and the long tail of PlantUML features.
Your documentation already renders PlantUML in a build pipeline you control.
You depend on specific PlantUML libraries or IDE plugins.

Choose Archgram if

You want to edit and preview without installing Java or running a server.
You use more than one notation and want to convert between them.
You want AI to draft a first diagram, and Git sync with pull requests.

Products change. This page describes approaches as we understand them; check each vendor’s current documentation before deciding.