Mermaid Live Editor: Markdown Mermaid Diagram Generator Online (Free SVG/PNG)

Q: Can I paste Mermaid diagrams with or without Markdown code fences (```mermaid)?

Yes. Our universal parser automatically detects both formats. You can paste pure Mermaid syntax (starting directly with graph TD, flowchart LR, sequenceDiagram, erDiagram, etc.) or paste code wrapped in Markdown fences (```mermaid or ~~~mermaid). The engine automatically unwraps the syntax for compilation and lets you export clean Markdown with a single click.

Q: How do I export Mermaid diagrams to high-resolution SVG or PNG images?

Click "Download SVG" in the action bar to save a clean, standalone vector file with embedded font metrics and styles, perfect for Figma, Illustrator, or responsive web embedding. To export for pitch decks or documents, click "Download PNG" to generate a 2x Retina rasterized image rendered on an in-RAM canvas with crisp typography.

Q: Is my diagram code or proprietary architecture uploaded to a server?

No. All diagram parsing, AST analysis, and SVG compilation take place 100% client-side in your web browser RAM using Mermaid.js. Zero bytes of your diagram code, proprietary architecture, or database schemas are ever transmitted over the network or saved to external storage, ensuring complete corporate privacy.

Q: Which Mermaid diagram types and syntax models are supported?

The editor supports all modern Mermaid.js diagram types, including Flowcharts (graph/flowchart), Sequence Diagrams (sequenceDiagram), Entity Relationship Diagrams (erDiagram), State Diagrams (stateDiagram-v2), Class Diagrams (classDiagram), Gantt Schedules (gantt), User Journey Maps (journey), Git Graphs (gitGraph), Pie Charts (pie), and Mindmaps (mindmap).

Q: How do I embed rendered Mermaid diagrams into GitHub, Notion, or Obsidian?

Click "Copy Markdown" in the action bar. The tool automatically formats your diagram into a standardized GitHub Flavored Markdown block with ```mermaid and closing ``` fences. You can paste this snippet directly into GitHub READMEs, Notion code blocks (set to Mermaid), Obsidian notes, or GitLab wikis for native rendering.

DIRECT ANSWER • MERMAID SPECIFICATION

Alex Zaremsky Markdown Mermaid Diagram Generator & Live Editor is a free, zero-latency web tool designed to render, edit, and export Mermaid.js diagrams directly in your web browser. Built on a 100% client-side in-RAM engine (Zero Server Upload), it compiles flowcharts, sequence diagrams, state machines, ER models, class hierarchies, and git graphs into clean vector SVG and 2x Retina PNG images in under 5 milliseconds. The tool features an intelligent universal normalizer that automatically parses both raw Mermaid code (starting directly with graph TD or sequenceDiagram) and fenced Markdown blocks (```mermaid), stripping or appending syntax fences on demand. Unlike cloud-dependent diagramming platforms that require account sign-ups and transmit private system architecture to remote servers, our in-browser workbench guarantees absolute document confidentiality while enabling instant one-click export for GitHub READMEs, Obsidian notes, Notion workspaces, and technical documentation.

📥

Click to browse or drag & drop your Mermaid or Markdown file here

Supports .mmd, .mermaid, .md, and .txt diagram files (Max 5MB)

🔒 100% In-RAM Local Processing — Zero Server Upload

MERMAID CODE Auto-Detect

0 chars 0 lines

INTERACTIVE VECTOR CANVAS (SVG) Flowchart

100%

● 100% In-RAM Engine (Zero Server Upload)

Engineered for High-Velocity Architectural Documentation

⚡

Universal Input Normalizer

Paste raw Mermaid syntax (graph TD) or Markdown code blocks (```mermaid). The engine automatically strips or wraps fences on demand without errors.

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100% In-RAM Local Privacy

Zero server uploads. Your proprietary system architecture, microservice topologies, and database schemas remain strictly inside your browser memory.

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Smooth Pan & Zoom Canvas

Navigate large-scale enterprise diagrams with ease. Drag to pan, scroll to zoom, reset to 100%, or fit the entire diagram to your viewport in one click.

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Multi-Theme Styling Engine

Switch instantly between Neutral, Default, Dark, and Forest vector themes. Styles are baked into exported SVG/PNG files with zero external CSS dependencies.

🖼️

2x Retina PNG & Vector SVG Export

Download clean SVG vector files for Illustrator/Figma or rasterize crisp 2x Retina PNG graphics for pitch decks, slides, and executive reports.

🛡️

Graceful Syntax Guard

Real-time linting catches syntax errors without crashing your browser. Helpful warning alerts isolate the exact line and issue while preserving previous work.

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1-Click Markdown & Embed Codes

Copy clean, formatted ```mermaid snippets with a single click for GitHub READMEs, Obsidian vaults, and Notion, or export standalone .mmd source files.

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Complete Diagram Family Support

Full out-of-the-box support for Flowcharts, Sequence Diagrams, ER Models, State Machines, Class Diagrams, Git Graphs, and Mindmaps with zero external plugins.

Mermaid Diagram Editor Comparison Matrix

Technical comparison of Alex Zaremsky Markdown Mermaid Editor against Mermaid Live Editor, MermaidChart, and PlantUML across client-side privacy, input flexibility, export formats, and latency.

Evaluation Metric	Alex Zaremsky Mermaid Suite	Mermaid Live Editor	MermaidChart	PlantUML Online
Client-Side Privacy (Zero Server Upload)	✓ 100% In-RAM Local	✓ Local Rendering	✗ Cloud Storage Required	✗ Server-Side POST Render
Universal Input (Raw & ```mermaid)	✓ Smart Auto-Unwrap	✗ Requires Raw Only	✗ Requires Raw Only	✗ Requires @startuml
Export Capabilities	SVG, 2x Retina PNG, MD, .mmd	SVG, PNG	SVG, PNG (Paid Tier)	PNG, SVG, ASCII
Interactive Pan & Zoom Controls	✓ Smooth Canvas Pan & Zoom	✓ Basic Pan/Zoom	✓ Pan/Zoom	✗ Static Image Only
Account Registration / Paywall	✓ 100% Free / No Signup	✓ 100% Free / No Signup	✗ Freemium / Account Req.	✓ Free / Open Source
Compilation Latency	< 5 ms (In-RAM)	~15 ms	~250 ms (Network sync)	~600 ms (Server HTTP)

How to Render, Edit, and Export Mermaid Diagrams in 3 Steps

Paste or Open Diagram Code

Paste your Mermaid diagram into the editor. You can paste pure raw Mermaid code (e.g., graph TD) or wrapped in Markdown code fences (```mermaid). You can also drag and drop a .mmd or .md file directly into the dropzone.

Inspect, Pan, Zoom, and Style

Inspect the instant vector rendering on the live canvas. Use the theme selector (Neutral, Default, Dark, Forest) and pan/zoom controls to inspect complex subgraphs and relationship nodes without lag.

Export SVG, PNG, or Copy Markdown

Click "Download SVG" for vector graphics, "Download PNG" for 2x Retina presentation slides, or "Copy Markdown" to copy a clean formatted code block for GitHub, Obsidian, or Notion.

Real-World Mermaid Architecture Showcases

Explore production-grade diagrams across cloud infrastructure, authentication, database schemas, and git flows. Click "⚡ Test in Editor" to load any diagram directly into the live canvas.

1. Cloud Infrastructure & API Gateway Flowchart

Multi-tier microservices with load balancer, auth verification, and database clustering.

graph TD
    Client[Web & Mobile Client] --> WAF[Cloudflare WAF / DDoS Guard]
    WAF --> ALB[Application Load Balancer]
    ALB --> Auth[Auth0 / OAuth2 Service]
    Auth -->|Token Valid| API[API Gateway Cluster]
    Auth -->|Invalid| Deny[401 Unauthorized]
    API --> SvcA[Billing Microservice]
    API --> SvcB[Analytics Microservice]
    API --> SvcC[LLM Inference Engine]
    SvcA --> PrimaryDB[(PostgreSQL Primary)]
    SvcB --> Clickhouse[(ClickHouse OLAP)]
    SvcC --> Redis[(Redis Cluster)]

2. OAuth2 Authorization Code & JWT Flow

Zero-trust sequence diagram detailing token exchange, PKCE verification, and API calls.

sequenceDiagram
    autonumber
    actor User as End User
    participant Browser as Client Application
    participant Auth as Identity Provider (IdP)
    participant API as Resource Server (API)

    User->>Browser: Click "Sign in with SSO"
    Browser->>Auth: GET /authorize?code_challenge=xyz
    Auth-->>User: Prompt Login & MFA
    User->>Auth: Submit Credentials & OTP
    Auth-->>Browser: Redirect with Authorization Code
    Browser->>Auth: POST /token + code_verifier
    Auth-->>Browser: Return ID Token & Signed JWT
    Browser->>API: GET /user/profile (Bearer JWT)
    API-->>Browser: 200 OK (User Data JSON)

3. SaaS Billing & Subscription Entity Relationship (ER)

Multi-tenant database schema modeling organizations, users, subscriptions, and invoices.

erDiagram
    ORGANIZATION ||--o{ USER : contains
    ORGANIZATION ||--|| SUBSCRIPTION : owns
    SUBSCRIPTION ||--o{ INVOICE : generates
    USER ||--o{ AUDIT_LOG : triggers

    ORGANIZATION {
        uuid id PK
        string name
        string tier
        timestamp created_at
    }
    USER {
        uuid id PK
        uuid org_id FK
        string email
        string role
    }
    SUBSCRIPTION {
        uuid id PK
        uuid org_id FK
        string plan_code
        string status
        timestamp current_period_end
    }
    INVOICE {
        uuid id PK
        uuid subscription_id FK
        numeric amount_due
        string currency
        string payment_status
    }

4. Git Feature Branching & Production Release Flow

Visual Git history showing feature branches, pull request merges, and release tagging.

gitGraph
    commit id: "Initial commit"
    commit id: "Setup CI/CD"
    branch develop
    checkout develop
    commit id: "feat: auth engine"
    branch feature/oauth
    checkout feature/oauth
    commit id: "feat: PKCE verify"
    commit id: "test: auth unit tests"
    checkout develop
    merge feature/oauth
    checkout main
    merge develop tag: "v1.0.0"
    checkout develop
    commit id: "feat: payments"

Frequently Asked Questions

Everything you need to know about rendering, editing, and exporting Mermaid diagrams online with zero server uploads.

Can I paste Mermaid diagrams with or without Markdown code fences (```mermaid)?

Yes. Our universal parser automatically detects both formats. You can paste pure Mermaid syntax (starting directly with graph TD, flowchart LR, sequenceDiagram, erDiagram, etc.) or paste code wrapped in Markdown fences (```mermaid or ~~~mermaid). The engine automatically unwraps the syntax for compilation and lets you export clean Markdown with a single click.

How do I export Mermaid diagrams to high-resolution SVG or PNG images?

Click "Download SVG" in the action bar to save a clean, standalone vector file with embedded font metrics and styles, perfect for Figma, Illustrator, or responsive web embedding. To export for pitch decks or documents, click "Download PNG" to generate a 2x Retina rasterized image rendered on an in-RAM canvas with crisp typography.

Is my diagram code or proprietary architecture uploaded to a server?

No. All diagram parsing, AST analysis, and SVG compilation take place 100% client-side in your web browser RAM using Mermaid.js. Zero bytes of your diagram code, proprietary architecture, or database schemas are ever transmitted over the network or saved to external storage, ensuring complete corporate privacy.

Which Mermaid diagram types and syntax models are supported?

The editor supports all modern Mermaid.js diagram types, including Flowcharts (graph/flowchart), Sequence Diagrams (sequenceDiagram), Entity Relationship Diagrams (erDiagram), State Diagrams (stateDiagram-v2), Class Diagrams (classDiagram), Gantt Schedules (gantt), User Journey Maps (journey), Git Graphs (gitGraph), Pie Charts (pie), and Mindmaps (mindmap).

How do I embed rendered Mermaid diagrams into GitHub, Notion, or Obsidian?

Click "Copy Markdown" in the action bar. The tool automatically formats your diagram into a standardized GitHub Flavored Markdown block with ```mermaid and closing ``` fences. You can paste this snippet directly into GitHub READMEs, Notion code blocks (set to Mermaid), Obsidian notes, or GitLab wikis for native rendering.