Mermaid | Diagramming and charting tool vs Excalidraw

Mermaid | Diagramming and charting tool and Excalidraw both land on Worth it.

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.

Worth it

Confidence: Medium

Buy the free, open-source version for quick diagrams and sketches . it costs nothing and reviewers love it.

Mermaid | Diagramming and charting tool versus Excalidraw
Compare	Mermaid \| Diagramming and charting tool	Excalidraw
Verdict	Worth it	Worth it
Best for	Developer docs and READMEs	Quick sketches and wireframes
Who it's not for	Non-technical teams wanting pure drag-and-drop	Enterprises wanting Miro-style workshop templates and facilitation
Privacy	13 public CVEs; recent 2025 XSS issues are medium severity . patch promptly if you embed Mermaid.	Open-source with past medium-severity XSS CVEs; Excalidraw+ adds SOC 2 certification and E2E encryption.
Support quality	No support evidence in reviewed sources.	No support evidence in sources
Public sentiment	Users value Mermaid as a lightweight, text-driven way to keep diagrams current, especially in docs and design reviews.¹³	Users love Excalidraw for quick, effortless sketching and rate it around 4/5, with minor gripes about scaling and drawing-tool limits.
Biggest gotcha	13 CVEs on record; 2025 XSS flaws need prompt patching, especially with untrusted input^⁶	Excalidraw+ ($7/mo) needed for team persistence and workspaces; free version stores locally