Free Database Diagram Tool for Easy Design and Management
For the developer or analyst who has to read, change or hand over a schema that has outgrown anyone's memory.
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The join you are about to write touches three tables you have never opened, and the person who designed them left the team. Point DbSchema at that database and it reverse-engineers the schema into an interactive diagram, so those three tables and the columns that join them are on screen before you write a line of SQL. The same diagram is where you rearrange the layout, edit a table, and export documentation for the next person who asks you the same question.
What a database diagram tool is and who needs one
A database diagram tool reads a schema and lays it out as a picture: a box for each table listing its columns, and a line wherever one table references another. Three jobs send people looking for one. Writing a correct join across tables you did not create. Working out what a column change would break before you ship it. Handing a new joiner something readable on their first day, so the answer does not have to come out of your head.
All three are the same problem: the schema is bigger than anyone's memory of it. If you are designing a structure from scratch instead, follow the step-by-step guide to designing a relational schema, which covers entities, keys and normalization in order.
Engines, where it runs, large schemas and team workflow
Start with the engines. A tool that draws PostgreSQL beautifully is no use for the MongoDB collection nobody documented, and the databases a company runs are rarely all of one kind. DbSchema connects over JDBC to any of 100+ SQL and NoSQL engines and downloads the driver for you.
Then ask where a diagram tool runs, because that decides where your schema goes. A browser tool needs the structure of your database on someone else's server; a desktop tool reads it from inside your own network. DbSchema is a desktop application, so the database never leaves its network, and there is no cloud account in the path.
The third question is what happens at scale. A schema with thousands of tables drawn on one canvas is a picture nobody can use, so a diagram tool has to let you split it. The fourth is the team workflow: how a schema change gets reviewed, and whether the design is a file you can put in Git or a document that lives in someone's account.
DbSchema: diagram-first design and reverse engineering
Connect DbSchema to a database and it reads the catalog and lays the tables out as a diagram, with a connector line for every declared foreign key. From there the diagram is editable: right-click the canvas and choose New Table, double-click a table header to open the Table Dialog and work on its columns, indexes and comments, or drag a column onto another table's column to draw a foreign key. Connected, each of those changes goes to the database as you make it.
Where the database declares no foreign keys, draw the relation anyway. A virtual foreign key is stored in the design model and never sent to the database, and DbSchema follows it exactly as it follows a real one when you browse data or build a query.
Two things follow from the design being a file. A schema change can be reviewed in Git alongside the code, and a model can be edited with no connection open and turned into a physical schema for the target engine later. Both the saved model file and the Git workflow that depends on it sit in Pro, not Community.
Free and Pro editions: what each one covers
The free Community Edition is not a trial. It covers all databases, connecting and reverse-engineering, interactive diagrams, creating and modifying tables, and the SQL editor, with no time limit.
Pro adds saving the model to a file, HTML5, PDF and Markdown documentation, the visual query builder, schema synchronization, relational data browse, the data generator and the data importer. Architect adds logical and conceptual design and own-key AI. The Pro trial runs 15 days and can be extended by another 15, on the same installation.
Working from the diagram: queries, data editing, HTML5 documentation
The diagram is where the work happens, not a picture you export and forget. Click a table header and the Query Builder opens with that table loaded, and you follow a foreign key to add the next one, ticking the columns you want and switching the join type on the line between them. Run SQL in the editor below the canvas. Hold Shift and Ctrl and click a table header and the Relational Data Editor opens on it, where selecting a row filters the child tables to the records that belong to it. The SQL editor is in Community; the query builder and relational data browse are Pro.
Documentation comes out of the same diagram. Choose Diagram → Export HTML5 or PDF Documentation and DbSchema writes one HTML5 package holding the diagram, the searchable table list, the columns and the comments, and it opens in any browser with nothing installed. That is what you send to an auditor or a new analyst instead of a screenshot. PDF and Markdown come from the same dialog, and all three are Pro.
To see what that output looks like, open the sample below.
Large schemas: layouts, subsets and navigation
One diagram of a whole enterprise database is unreadable, so DbSchema does not draw one. A project holds as many diagrams as you like over the same schema, each with its own layout and its own set of tables, which is how thousands of tables stay navigable: an e-commerce database gets separate diagrams for customers, inventory and orders, and a banking database gets accounts, transactions and audit logs.
Inside one diagram, related tables can be clustered into a named, coloured group you move as a unit, and Diagram → Auto Arrange lays out a freshly reverse-engineered schema that came back overlapping. Each diagram is a working subset; the rest of the schema stays one tab away.
Choose on where a diagram tool runs and on what the diagram has to become afterwards. For a schema that stays inside your network and ends up as documentation and a version-controlled model, download DbSchema and point it at your own database: the free Community Edition reverse-engineers it into an interactive diagram, and the Pro trial in the same installer adds the HTML5, PDF and Markdown documentation and the visual query builder described above. If you are designing the structure rather than reading it, start from the relational schema design guide instead.
Frequently asked questions
Is there a genuinely free database diagram tool?
The DbSchema Community Edition never expires, and the 15-day Pro trial packed into the same installer asks for no credit card. What Community covers, and where Pro starts, is in the editions section above.
Can a database diagram tool create the database as well as draw it?
DbSchema generates the physical schema for the target engine from the design model, and compares an existing database against that model in the Synchronization Dialog, where each difference is applied, taken into the model, or written out as migration SQL. Schema synchronization is Pro.
How do I document a database for people who do not write SQL?
Write the explanation into the Description field of each table and column first. DbSchema carries those descriptions into the HTML5 export as mouse-over tooltips on the table and column names, which is what makes the export readable to someone who cannot read the DDL. Exporting the documentation is a Pro feature.
See your own database as a diagram
DbSchema connects to any of 100+ SQL and NoSQL engines, reverse-engineers the schema into an interactive diagram, and keeps large schemas readable one subsystem at a time.
