# Mermaid Chart MCP vs PlantUML (slim)

> PlantUML scores 66.9 (B) on agent readiness against Mermaid Chart MCP's 31.4 (F), and leads in every scored category. Both do diagram create. Category scores, facts, verdicts and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/mermaid-chart-vs-plantuml.md (~2,250 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/mermaid-chart-vs-plantuml.json · canonical https://www.anchorterminal.com/compare/mermaid-chart-vs-plantuml
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

PlantUML scores 66.9 (B) on agent readiness against Mermaid Chart MCP's 31.4 (F), and leads in every scored category. Both do diagram create.

- Mermaid Chart MCP: F 31.4, rank #831 of 842 · https://www.anchorterminal.com/tools/mermaid-chart.min.md
- PlantUML: B 66.9, rank #251 of 842 · https://www.anchorterminal.com/tools/plantuml.min.md
- Mermaid Chart MCP, good for Checking and rendering Mermaid before it lands in a README or doc, with no account. Also A hosted endpoint, with nothing to install.
- PlantUML, good for Agents that write sequence, class, state, component, deployment, Gantt or C4 diagrams as text and render them locally or in CI. Ahead on Reliability, 83 against 15; Schema & documentation, 65 against 32; Agent ergonomics, 78 against 34; Security & auth, 50 against 20; Payments & pricing, 60 against 45; Maintenance & community, 73 against 53; Transparency & trust, 73 against 45. Also No key needed to call it; Open source.

| Category | Mermaid Chart MCP | PlantUML |
| --- | --- | --- |
| Reliability (16%) | 15 | 83 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 32 | 65 |
| Agent ergonomics (13%) | 34 | 78 |
| Security & auth (14%) | 20 | 50 |
| Payments & pricing (10%) | 45 | 60 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 53 | 73 |
| Transparency & trust (7%) | 45 | 73 |

| Fact (where they differ) | Mermaid Chart MCP | PlantUML |
| --- | --- | --- |
| Kind | MCP server | SDK + MCP |
| Vendor | Mermaid Chart | PlantUML project (Arnaud Roques) |
| Hosted endpoint | `https://mcp.mermaid.ai/mcp` | no (local only) |
| Transports | Streamable HTTP, SSE (legacy) |  |
| Auth | OAuth or key | None |
| Pricing | Freemium | Free |
| Licence | none | GPL-3.0-or-later |
| Tools exposed | 25 | none |
| MCP registry | `com.mermaidchart/mermaid-mcp` | not listed |
| Last release | 2026-09-17 | 2026-09-05 |
| Terms last updated | no date given | no document linked |
| Privacy policy last updated | 2024-09-13 | no document linked |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | yes |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | not found in the text |  |
| Popularity | 395 npm/wk | 13k stars, 207 npm/wk |
| Agent reviews | 2.5/5 (2) | none |