ERD Diagram Maker

What this ERD editor generates

The editor uses structured inputs rather than a raw text language. Its generated Mermaid describes the entity names, field types, PK and FK markers, and the relationships you selected. For example, a small order model can produce:

erDiagram
  CUSTOMER ||--o{ ORDER : places
  ORDER ||--|{ ORDER_ITEM : contains
  CUSTOMER {
    int customer_id PK
    string email
  }
  ORDER {
    int order_id PK
    int customer_id FK
  }
  ORDER_ITEM {
    int order_id FK
    int quantity
  }

Roles and cardinalities

Mermaid uses crow’s-foot markers for these cardinalities. The tool generates that syntax from the relationship choices, so you can copy the Mermaid text without hand-writing it.

Limits, exports and privacy

• An ERD can contain up to 12 entities and up to 20 fields in each entity.
• SVG is useful for documentation that must remain sharp when scaled. PNG is a bitmap export for places that need an image file.
• Mermaid text can be copied for a Mermaid-compatible document or renderer. JSON export and import are local project files.
• The editor does not generate DBML or SQL. It also has no server project store, uploads, synchronization, node dragging or manual node reordering.
• In funnel mode, project data is kept only in private tab sessionStorage for up to 30 minutes. It is not placed in the URL or sent through Livewire.