Design Database Schemas Online for Free
Planning the structure of a relational database is a critical step in software development. Visualizing tables, primary keys, foreign keys, and how they interact makes spotting design flaws much easier. Our Free Database ER Diagram Tool allows developers, students, and system architects to quickly generate Entity-Relationship diagrams without wrestling with complex drag-and-drop vector software.
Text-to-Diagram Generation
Instead of manually drawing boxes and connecting lines, this tool uses the popular Mermaid.js syntax. You simply type your database rules using a plain text, Markdown-like language, and the application instantly renders a professional ER diagram. This "diagrams-as-code" approach is faster, easily version-controlled, and highly repeatable.
How to Use the Free ER Diagram Maker
- Write your syntax: In the left-hand code editor, define your database entities (tables), attributes (columns), and their relationships (one-to-one, one-to-many, etc.). You can click "Load Example" to see the basic format.
- Live Preview: As you type, the right-hand panel continuously interprets your code and updates the visual diagram. Syntax errors will be caught and displayed immediately.
- Export: Click the "Download SVG" button to instantly save a scalable, high-resolution vector image of your completed schema design, perfect for embedding in documentation or engineering wikis.
Frequently Asked Questions
What is an ER Diagram?
An Entity-Relationship (ER) diagram is a flowchart that illustrates how "entities" such as people, objects, or concepts relate to each other within a system. They are widely used in software engineering and database design.
What syntax does this tool use?
This tool utilizes Mermaid.js syntax. It is a simple text language used to generate charts and diagrams. You define entities, relationships (like one-to-many), and attributes using plain text.
Does this connect to my real database?
No. This is strictly a design and mock-up tool. It does not connect to MySQL, PostgreSQL, or any live database server, nor does it generate SQL export code. All rendering happens safely within your browser.