Mermaid vs PlantUML
A data-driven comparison of two Diagrams as code: popularity, development activity, licensing and installation. Updated .
MermaidGenerate diagrams and flowcharts from markdown-like text definitions, with a live editor.
PlantUMLGenerates UML, Gantt, mind map and other diagrams from plain text.
Key differences
- Mermaid has 6.8× as many GitHub stars as PlantUML (90.5K vs 13.4K).
- Mermaid had more development activity over the last 12 months: 2,472 commits vs 846.
- Mermaid is licensed under MIT; PlantUML under LGPL-3.0.
- Mermaid is written primarily in TypeScript, PlantUML in Java.
- PlantUML is the older project: its repository was created in 2010, Mermaid's in 2014.
By the numbers
- Mermaid
- PlantUML
Show data as a table
| Metric | Mermaid | PlantUML |
|---|---|---|
| GitHub stars | 90,531 | 13,352 |
| Commits, last 12 months | 2,472 | 846 |
| Contributors | 365 | 131 |
| Forks | 9,322 | 1,235 |
Development activity
Commits per month to each default branch, last 12 complete months.
- Mermaid
- PlantUML
Show data as a table
| Month | Mermaid | PlantUML |
|---|---|---|
| Oct 2025 | 63 | 42 |
| Nov 2025 | 143 | 48 |
| Dec 2025 | 61 | 27 |
| Jan 2026 | 89 | 48 |
| Feb 2026 | 186 | 101 |
| Mar 2026 | 230 | 140 |
| Apr 2026 | 277 | 50 |
| May 2026 | 435 | 111 |
| Jun 2026 | 327 | 67 |
| Jul 2026 | 75 | 43 |
| Aug 2026 | 331 | 76 |
| Sep 2026 | 255 | 93 |
Side by side
| Attribute | Mermaid | PlantUML |
|---|---|---|
| Description | Generate diagrams and flowcharts from markdown-like text definitions, with a live editor. | Generates UML, Gantt, mind map and other diagrams from plain text. |
| Category | Diagrams as code | Diagrams as code |
| License | MIT | LGPL-3.0 |
| Language | TypeScript | Java |
| Status | Active | Active |
| Latest release | @mermaid-js/tiny@12.1.0 () | v1.2026.8 () |
| Last commit | ||
| Repository created | ||
| Open issues | 1,482 | 575 |
| Install | npm install mermaid | implementation("net.sourceforge.plantuml:plantuml:1.2025.4") |
Which should you choose?
Popularity and activity are only part of the story. Consider which ecosystem you work in, the chart types and interactions you need, how much data you render, and whether the license fits your project. Both tool pages list alternatives if neither is quite right.
-
Mermaid
Generate diagrams and flowcharts from markdown-like text definitions, with a live editor.
-
PlantUML
Generates UML, Gantt, mind map and other diagrams from plain text.