Question 1

Why text-based diagrams instead of a visual editor?

Accepted Answer

Three reasons: **diffs** (a one-line code change shows as a one-line diagram change in git, instead of a binary blob nobody can review), **collaboration** (PR comments can suggest specific edits to the diagram source), and **automation** (you can generate diagrams from your codebase, e.g., dependency graphs from package.json, ER diagrams from your Prisma schema). The trade-off is a small learning curve. For one-off whiteboard-style diagrams, draw.io or Excalidraw remain faster.

Question 2

What diagram types does Mermaid support?

Accepted Answer

**flowchart** (TD/LR), the most common, for general flows. **sequenceDiagram**, actor-to-actor message passing. **classDiagram**, UML classes with properties/methods. **erDiagram**, entity-relationship for databases. **stateDiagram-v2**, state machines. **gantt**, project timelines. **pie**, pie charts. **journey**, user journey maps. **gitGraph**, branch/commit visualization. **C4Context/Container/Component**, C4 architecture diagrams. **mindmap, timeline, quadrantChart, requirementDiagram, sankey**, newer additions. Most projects use flowchart, sequenceDiagram, and erDiagram 90% of the time.

Question 3

How do I export to PNG/SVG?

Accepted Answer

SVG is always available, the renderer's native output. Right-click the rendered diagram → 'Save image as' or use the download button. PNG is rasterized from the SVG using a canvas; pick the resolution that matches your target (e.g., 2× for retina displays in docs). SVG is the right pick for documentation that gets zoomed (README on GitHub, technical docs) because it stays crisp at any scale; PNG is the right pick for Slack/email pasting where SVG support is inconsistent.

Question 4

Does GitHub render Mermaid in Markdown?

Accepted Answer

Yes, since 2022, GitHub renders Mermaid code blocks in any Markdown file, including READMEs, PR descriptions, and issue comments. Use a fenced code block with `mermaid` as the language: ```` ```mermaid
flowchart LR
 A --> B
``` ````. GitLab, Notion, Obsidian, Forgejo, and many static site generators do the same. This means a diagram you create here can drop straight into a README and render automatically, no image hosting needed.

Question 5

What's the difference between flowchart TD and LR?

Accepted Answer

Layout direction. **TD** (top-down) is good for hierarchies and decision trees, flows that start at one point and branch downward. **LR** (left-right) is good for pipelines and sequences, A → B → C → D. Two more: **BT** (bottom-top, rare) and **RL** (right-left, rare). Pick by what reads naturally for your data. Decision trees almost always want TD; build pipelines almost always want LR.

Question 6

Is the diagram source sent anywhere?

Accepted Answer

No. Mermaid.js is bundled in the page and renders entirely in the browser. Your diagram source, sometimes containing internal architecture details, customer data flows, or unreleased product structure, stays in the tab. Open DevTools Network during rendering: zero outbound requests.

Question 7

What standards does Mermaid Diagram Editor validate against?

Accepted Answer

Mermaid Diagram Editor checks compliance with Mermaid.js diagram syntax.

Question 8

What are the limitations of Mermaid Diagram Editor?

Accepted Answer

Rendering depends on Mermaid.js version Complex diagrams may cause browser slowdown Does not support all Mermaid diagram types equally

Type	Identifier	Primary Use Case	Complexity
Flowchart	`flowchart`	Logic, Pipelines, Decisions	Standard
Sequence	`sequenceDiagram`	API Flows, Inter-service Auth	Standard
ER Diagram	`erDiagram`	DB Schema, Data Modeling	Standard
Gantt	`gantt`	Project Timelines, Roadmaps	Advanced
State	`stateDiagram-v2`	Lifecycle, FSM behavior	Advanced

Mermaid Diagram Editor

Live Rendering

Visual Output

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What is Mermaid Diagram Editor?

Frequently Asked Questions

Technical Deep Dive

Mermaid Diagram Editor

Live text-to-diagram

Export SVG & PNG

Architecture stays private

01 Diagram Capability Matrix

02 Visualization Pipeline Workflow

Runs 100% in your browser

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