MyMapDescribe your schema
Tell us about your entities, tables, or data model. Include relationships (one-to-many, many-to-many) if you know them.
ER Diagram Maker
Describe your database entities, tables, or data model and AI builds an ER diagram — tables, columns, primary keys, and relationships.
✦Free to try · No signup required · PDF, docs & images supported
Simple by design
How it works
AI builds the diagram
MyMap's AI generates an ER diagram with entity boxes, attributes, primary keys, and relationship lines.
Refine and export
Add columns, change relationships, or ask AI to extend the schema. Export as PNG or PDF for docs or wikis.
About the framework
What is an ER Diagram?
An entity-relationship (ER) diagram is a visual representation of a database's structure — showing the entities (tables), their attributes (columns), and the relationships between them. It's the standard tool for database design and documentation, used before writing a single line of SQL to ensure the data model is correct.
The ER diagram notation was introduced by Peter Chen in 1976 and remains the foundational language of relational database design. Modern variants include Crow's Foot notation, which is widely used in tools like Mermaid, Lucidchart, and draw.io.
What an ER diagram shows
- Entities — the main objects or tables (Users, Orders, Products)
- Attributes — the fields within each entity (id, name, email, created_at)
- Primary keys — the unique identifier for each entity
- Relationships — how entities connect (a User has many Orders)
- Cardinality — the quantitative nature of each relationship (one-to-one, one-to-many, many-to-many)
ER diagrams are used in backend architecture, schema reviews, API design, and technical documentation to give developers and stakeholders a shared view of the data model.
MyMap's AI generates a complete, correctly structured ER diagram from a plain-language description of your database entities and relationships — no SQL or diagramming syntax required.
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Frequently asked questions
Common questions
Is the ER diagram maker free?
Yes — you can create ER diagrams for free without signing up. Free accounts get a generous number of AI messages per month.
Does it support many-to-many and one-to-one?
Yes. Describe your cardinality (one-to-many, many-to-many, one-to-one) and the AI will render the appropriate relationship notation in the diagram.
ER Diagram Maker
Free to start. No credit card required.
✦Free to try · No signup required · PDF, docs & images supported