Diagrams generated from plain-text syntax, renderable inside Markdown.
Why we recommend it
Because diagrams are text, they live in the repo next to the code and stay reviewable in pull requests — the fix for documentation diagrams that silently go stale.
Strengths
- Diagrams version-control properly as text
- Renders natively in GitHub, GitLab and Notion
- No separate tool to open or licence
Keep in mind
- Limited layout control — the engine decides positioning
- Complex diagrams become hard to read
- Not suited to freeform or visually designed diagrams
How much does Mermaid cost?
Free — Free.
List price, excluding tax. Compare prices across the directory.
Mermaid alternatives and related tools
Cal.com
Open-source scheduling infrastructure — a self-hostable Calendly alternative.
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draw.io (diagrams.net)
Diagramming for flowcharts, wireframes and architecture, with no account required.
Free
Excalidraw
Excalidraw is a free, open-source whiteboarding tool for sketching diagrams and flowcharts. Simple, fast, and no sign-up required.…
Free60 AI prompts for general & business — ready-to-copy prompts for this discipline, organised alongside the directory. Browse general & business prompts →