ER डायग्राम मेकर.

Up to 50,000 characters of Mermaid code and 800 connections. PNG export up to 32 megapixels. Share links are limited to diagrams that compress to about 12,000 characters. Mermaid 11 syntax; no real-time collaboration or cloud storage.

Relationships use crow’s foot notation: || means exactly one, o| zero or one, |{ one or more and o{ zero or more. The tool draws the model; it does not connect to a database or generate SQL. Rendering uses the open-source Mermaid library in your browser with its strict security level, so links, scripts and HTML in labels are disabled. Drafts are saved in this browser only; share links store the compressed code in the part of the URL after #, which browsers do not send to the web server. Exports contain only what you drew.

CUSTOMER ||--o{ ORDER : places → one customer places zero or more orders.