Build ER Diagrams Instantly

An ER diagram tool is software that lets you create entity relationship diagrams — visual models showing how tables (entities), their columns (attributes), and their connections (relationships) are structured in a relational database. MakeCharts provides a free online ER diagram tool with AI-powered generation, key designation, cardinality controls, and export options.

Simply describe your database schema in plain language — for example, 'A customer places many orders, each order has multiple products.' The AI interprets your description and generates a complete ERD with entities, typed attributes, primary and foreign keys, and labeled relationships. You can then refine any detail in the visual editor.

Yes — you can create, edit, and export ER diagrams for free with no signup required. Free accounts also include AI credits to generate ERDs from natural language descriptions. Paid plans unlock more AI credits, file uploads, and advanced export options.

The tool supports PK (Primary Key), FK (Foreign Key), UK (Unique Key), and combined PK+FK designations. You can assign these to any attribute in any entity, and they are visually distinguished in the rendered diagram so relationships are immediately clear.

Yes. The ER diagram tool supports unlimited entities and attributes, multiple cardinality types (exactly-one, zero-or-one, one-or-more, zero-or-more), identifying and non-identifying relationships, and flexible layout directions. It handles schemas ranging from a few tables to large multi-entity data models.

You can set cardinality on both sides of every relationship: exactly-one, zero-or-one (optional), one-or-more, or zero-or-more. This lets you accurately model required vs optional participation and one-to-one, one-to-many, or many-to-many cardinality in your entity relationship diagram.

Yes. You can download your ERD as a high-resolution PNG or SVG file, generate a shareable link, or copy an embed code to add the diagram to a website or documentation platform like Confluence or Notion.

Yes — you can build and export ER diagrams without creating an account. Sign up for free to save your diagrams, access more AI generation credits, and share diagrams via persistent links.

An identifying relationship means a child entity's existence depends on the parent — its primary key includes the parent's primary key as a foreign key. A non-identifying relationship means the child can exist independently. The ER diagram tool lets you specify both types for accurate data modeling.

Yes. You can switch between top-to-bottom, bottom-to-top, left-to-right, and right-to-left layout directions at any time. This is helpful for fitting wide or deep schemas clearly within a diagram without overlapping entities.