See complex diagrams clearly Small-team pricing
Enterprise-grade modeling No cloud uploads.
Your work stays yours.
Luna Modeler
Data Modeling & Database Design Tool.
Model offline, then generate the SQL.
- More than just static ER diagrams Start data modeling from scratch or reverse-engineer databases
- Stop schema drift Compare dev, staging & production and generate synchronisation SQL
- Works fully offline
Your schemas stay on your device, nothing uploaded to the cloud, ever - One-time purchase Pay once, use forever.
No subscription, no lock-in
Model First.
Then Generate the SQL.
A database GUI draws a picture of the database you already have. A data modeling tool lets you design the one you don't have yet — offline, with no connection required — and then generates the DDL and ALTER scripts to make it real. Luna Modeler does both: design from scratch, or reverse-engineer an existing database and keep the model in step with it.
choose Luna Modeler
- Works with Oracle, SQL Server, PostgreSQL, MySQL, MariaDB & SQLite
- Enterprise-grade modeling at a fraction of the typical price
- Keeps your live database and your data model in sync
- Draws ER diagrams and generates deployment-ready SQL
- Turns any diagram into interactive documentation
- Headless CLI, git-friendly folder format (Ultimate edition)
Complex Diagrams, Instantly Readable
Once a model grows past a few dozen tables, finding what connects to what becomes guesswork. Context Lens ends that: select any table, view, or object and it opens a focused view of everything linked to it — relationships, dependencies, every line leading elsewhere — no more scrolling a 200-table diagram to answer "what does this touch?"
What Database Professionals Say
Platform-Specific SQL for Every Database in Your Stack
Luna Modeler doesn't generate generic SQL that breaks at deployment. Every forward-engineered script matches your database's exact dialect.
- PostgreSQL — PostGIS types, Supabase, AWS RDS for PostgreSQL
- Oracle Database — on-premise, AWS RDS Oracle, Oracle Cloud
- SQL Server — Azure SQL Database, Entra ID auth
- MySQL and MariaDB — open-source stacks
- SQLite — embedded, file-based, and mobile application databases
Your Schemas Never Leave Your Machine
Luna Modeler is a desktop application. Your database credentials, ER diagrams, schema files, and generated SQL are stored on your own device only. No account required to use it. No schemas uploaded to our servers.
Your intellectual property stays in your hands.
No credit card. No account. Just download and start designing.
- Free 14-day trial
- No credit card required
How to Choose a Data Modeling Tool
Most tools in this category are compared on how their diagrams look. That is the least useful question.
A diagram is an output; what matters is what the tool can do before and after the picture exists.
Six questions separate a data modeling tool from a database GUI that happens to draw boxes.
1. Does it work without a database connection?
A database GUI needs a live server before it can show you anything, because it reads the structure from the database itself. A data modeling tool holds the model independently, so you can design a structure that does not exist yet, hand it to a colleague for review, or work on a train with no VPN. If the tool cannot open without a connection string, it is a client, not a modeling tool.
2. Does it generate SQL in your dialect?
Generic DDL is easy. Correct DDL is not. Oracle packages and sequences, PostgreSQL domains, composite types and enums, SQL Server user-defined types — each dialect has constructs the others do not, and a tool that flattens them into lowest-common-denominator SQL produces scripts you then have to fix by hand. Check that the tool generates what the target database actually accepts.
3. Can it compare a model against a live database?
This is where the category earns its keep. Schema drift is inevitable: dev moves ahead of staging, someone patches production directly. A modeling tool should compare your model to any environment, show exactly what differs, and generate the ALTER script that closes the gap — so every change is reviewed before it runs, and applied at once rather than piecemeal.
4. Can you draw what the database doesn't know?
A database GUI draws only what sits in the catalogue: tables, columns, keys. Luna Modeler adds what explains them — flowchart and data flow elements, lineage arrows showing where a field came from, ownership and sensitivity flags for an auditor — on the same canvas as the tables. That context belongs in a picture, not in a folder of AI-generated Markdown almost nobody carefully reads.
5. Where does your schema live?
Your database structure describes your business: table names, relationships, what you store about customers. Browser-based tools upload that to someone else's infrastructure. For regulated industries, government work, or client projects under NDA, that is often the question that decides the tool — and it is worth answering before the procurement review, not during it.
6. What happens when you stop paying?
Under a subscription, access to your own models usually ends with the invoice. Under a perpetual licence, the version you bought keeps working indefinitely and updates are optional. Neither is automatically right, but the difference matters most at the point you are least able to act on it — so decide deliberately rather than by default.
- Data modeling, ER diagrams
- Unlimited projects, unlimited tables
- Reverse & forward engineering
- SQL scripts generation
- Custom fields & customization
- Templates for custom output
- Assets & graphics
- All basic edition features
- Advanced reverse engineering
- Secure SSH/TLS connections
- Sub-diagrams
- Interactive reports
- Synchronization features
- Model conversion
- Multiple instances
- All professional edition features
- Navigator for easy schema exploration
- Folder based format for team collaboration
- Command line interface
- CLI configuration wizard
Switching from another tool? See how Luna Modeler compares to erwin, ER/Studio, PowerDesigner, dbdiagram.io, Toad Data Modeler and Vertabelo.
Also working with
MongoDB or GraphQL?
Luna Modeler covers relational databases. If your stack also reaches into MongoDB or GraphQL, we built a dedicated tool for each — same one-time pricing, same offline-first design.
Data Modeling Tool
for MongoDB & noSQL
- Visual MongoDB schema design
- Reverse engineer existing MongoDB databases
- Generate validation & creation scripts
- Mongoose ODM support
Schema Design Tool
for GraphQL
- Visual GraphQL schema design
- Import from files or live URLs
- Generate schema definition scripts
- Export to PDF documentation
What is the difference between a data modeling tool and a database design tool?
In practice the two terms describe the same category and are used interchangeably.
Database design tool tends to be used when the focus is a single relational database and its tables, keys and constraints. Data modeling tool tends to be used when the work spans conceptual, logical and physical models, several database platforms, or documentation that outlives any one schema.
Both describe software that lets you design a structure visually and generate the SQL to build it — which is what separates either from a diagram editor.
Can I design a database structure before the database exists?
Yes, and that is the main thing separating this category from a database GUI.
A data modeling tool holds the model independently of any server, so you can design tables, columns, keys and relationships with no connection at all, review the design with your team, and only then generate the DDL that creates it. Datensen tools run entirely on your own machine, so no connection is required at any point.
How does a data modeling tool apply changes to an existing database?
By comparison, not by guesswork. You change the model, then compare it against the target database — development, staging or production.
The tool reports exactly what differs and generates an ALTER script that closes the gap. You review that script before it runs, and every change is applied together rather than piecemeal, which is what keeps environments from drifting apart.
Which data modeling tool should I choose for PostgreSQL, MongoDB or GraphQL?
Luna Modeler covers relational databases — PostgreSQL, Oracle, SQL Server, MySQL, MariaDB and SQLite.
Moon Modeler covers MongoDB, Mongoose, Amazon DocumentDB and Azure Cosmos DB. Galaxy Modeler covers GraphQL schemas.
Merit Modeler is free, and covers flowcharts, data flow diagrams and use case diagrams rather than database schemas.
They are separate products with the same offline-first design and the same one-time pricing, so a mixed stack does not mean a compromise on any one platform.
Is there a data modeling tool for macOS and Linux?
Yes. Luna Modeler, Moon Modeler and Galaxy Modeler are desktop applications that run natively on Windows, macOS and Linux, with the same features on each.
This matters in this category because several long-established database design tools remain Windows-only, which leaves macOS and Linux users running a virtual machine to model a database.
How much does a data modeling tool cost?
Luna Modeler and Moon Modeler start at $99 USD for a perpetual licence — you pay once and keep using that version indefinitely, with no subscription.
Annual update renewals are optional and only needed if you want newer versions. Every tool has a free 14-day trial that requires no credit card and no account. Full details are on the pricing page.