Mermaid | Diagramming and charting tool
Worth it
Confidence: Medium
Buy if you're a developer or docs team that wants diagrams as versioned text . it's free, open source, and embedded everywhere.
New check
Comparison
Mermaid | Diagramming and charting tool vs PlantUML.com
Mermaid | Diagramming and charting tool and PlantUML.com both land on Worth it.
PlantUML.com
Worth it
Confidence: Medium
Developers and docs teams should use it . it's free, open source, and diagrams live as versionable text.
| Compare | Mermaid | Diagramming and charting tool | PlantUML.com |
|---|---|---|
| Verdict | Worth it | Worth it |
| Best for | Developer docs and READMEs | Developers diagramming architecture as code |
| Who it's not for | Non-technical teams wanting pure drag-and-drop | Non-technical teams wanting drag-and-drop drawing |
| Privacy | 13 public CVEs; recent 2025 XSS issues are medium severity . patch promptly if you embed Mermaid. | A few public CVEs, mostly affecting server deployments; patch promptly and avoid exposing servers unpatched. |
| Support quality | No support evidence in reviewed sources. | No support evidence found |
| Public sentiment | Users value Mermaid as a lightweight, text-driven way to keep diagrams current, especially in docs and design reviews.13 | Public sources describe PlantUML as a versatile, comprehensive free text-based diagramming tool popular with developers for documentation. |
| Biggest gotcha | 13 CVEs on record; 2025 XSS flaws need prompt patching, especially with untrusted input⁶ | Fedora 2024 high-severity type-confusion fixes; run the latest release |
Pick Mermaid | Diagramming and charting tool when
- Developer docs and READMEs
- Markdown-native teams
- Architecture and sequence diagrams
- Git-versioned diagram workflows
When Mermaid | Diagramming and charting tool is not a fit
- Non-technical teams wanting pure drag-and-drop
- Polished sales or marketing visuals
- Apps rendering untrusted diagram input unpatched
- Teams needing vendor support SLAs
Pick PlantUML.com when
- Developers diagramming architecture as code
- Docs-heavy engineering teams
- Teams versioning diagrams in Git
- Anyone wanting free UML with no licenses
When PlantUML.com is not a fit
- Non-technical teams wanting drag-and-drop drawing
- Buyers needing vendor support or SLAs
- Polished exec-deck diagrams . use a presentation tool
- Overkill for one-off flowcharts . a whiteboard does it
Sources
- Mermaid official sitemermaid.js.orgofficial
- mermaid-js/mermaid on GitHubgithub.comofficial
- Google Workspace Marketplace listing (4.4/5, 111 reviews)workspace.google.comreview
- TechCrunch on Mermaid Charttechcrunch.comnews
- Pulse2 . Mermaid Chart profile, 8M userspulse2.comnews
- SentinelOne . CVE-2025-54881sentinelone.comsecurity
- VulDB . CVE-2025-54880vuldb.comsecurity
- NVD search . Mermaid CVEsnvd.nist.govsecurity
- OpenCVE . 13 Mermaid CVEsopencve.alliance.unm.edusecurity
- Mermaid security pagemermaid.js.orgsecurity
- JetBrains WebStorm Mermaid.js supportblog.jetbrains.comnews
- Grafana Mermaid plugin docsgrafana.comofficial
- Stanley Lim . Why I choose Mermaidblog.stanleylim.mereview
- Reddit r/ProductManagement threadreddit.comreview
- Mermaid cheatsheet . 19 diagram typesmermandraw.comreview
- Microsoft engineering playbookmicrosoft.github.ioofficial