dbdiagram.io is a browser-based tool for drawing database diagrams using a text-based markup language called DBML. You type table definitions in a code editor, the tool renders the diagram, and your schemas are stored in the cloud. For developers who prefer a code-first workflow and are comfortable with cloud storage, it works well.
For teams that need to work offline, prefer a visual drag-and-drop canvas, want a perpetual license instead of a recurring subscription, or require that schemas never leave their own infrastructure, it does not. This page explains why those teams choose Luna Modeler instead.
The core difference: offline-first vs. browser-only
dbdiagram.io runs entirely in the browser. If you lose your internet connection, you lose access to your tool. Your diagrams are stored on dbdiagram's servers, which means a third party holds the structure of your data — table names, field definitions, relationships, and business logic encoded in your model. For engineers in regulated industries, air-gapped environments, or organizations with strict data residency requirements, that architecture is a hard blocker.
Luna Modeler is a desktop application for Windows, macOS, and Linux. Your schemas are stored as local .dmm files on your own machine. Core modeling functionality — creating diagrams, generating SQL, reverse engineering, exporting reports — works fully without an internet connection. Nothing leaves your environment unless you explicitly export or share it.
This is not a configuration option. It is the architecture. Full details on data privacy are documented here.
Visual canvas vs. code editor
dbdiagram.io uses DBML — a text markup language — as its primary interface. You write code to define tables and relationships, and the diagram updates accordingly. This is an efficient workflow for developers who are comfortable writing schema definitions by hand and want a quick way to visualize them.
Luna Modeler offers a visual canvas. You create tables, add columns, and draw relationships directly on the diagram. There is no markup language to learn. This makes it more accessible for database administrators, architects, and analysts who think spatially about their schema rather than in terms of code. Complex diagrams with dozens of tables are easier to navigate and reorganize visually than in a text file.
Both approaches are valid. The right choice depends on how your team thinks about database design.
Subscription vs. perpetual license
dbdiagram.io offers a free tier with limitations and paid plans. Team and enterprise plans add collaboration features and centralized workspaces. What happens when you stop paying? Will your diagrams remain locked in a cloud service you no longer control?
Luna Modeler is sold under a perpetual license. You pay once. Your project files are plain files on disk — they belong to you. Optional annual update plans are available for new features, but they are genuinely optional. The version you purchased continues to work after any renewal lapses.
Forward and reverse engineering
dbdiagram.io focuses on diagramming. You can export your diagram as SQL DDL for PostgreSQL or MySQL, which is useful for quick prototyping. It does not offer ALTER script generation, or schema synchronization.
Luna Modeler is built for the full data modeling lifecycle:
- Visual ER diagram creation for Oracle, PostgreSQL, SQL Server, MySQL, MariaDB, and SQLite
- Forward engineering with platform-specific SQL DDL
- Reverse engineering from live databases — import an existing schema directly into a visual model
- ALTER script generation for synchronizing schema changes between model versions
- Schema conversion between database platforms
- Interactive HTML documentation reports for sharing with stakeholders
- Works fully offline — no internet connection required
- Runs natively on Windows, macOS, and Linux
The honest case for Luna Modeler
dbdiagram.io is a capable, developer-friendly tool for quickly sketching a database schema and sharing it via a link. If your workflow is entirely browser-based, you prefer code-driven diagram generation, and you are comfortable with your schemas stored in the cloud, it is a reasonable choice.
Luna Modeler is the right choice when any of the following apply: you need to work offline, your organization requires that schema data never leaves your own infrastructure, you prefer a visual canvas over a code editor, you need reverse engineering for comparison and ALTER script generation, or you want to avoid recurring subscription costs for professional tooling.
Try Luna Modeler free for 14 days
Can I use Luna Modeler without an internet connection?
Yes. Core modeling functionality works fully offline. License activation requires a one-time internet connection. After that, the tool operates without network access.
Are my schemas stored on Datensen's servers?
No. Your project files are stored on your local filesystem. Nothing is uploaded to cloud or any third party. Full privacy details here.
What happens to my models if I stop renewing the Luna Modeler update subscription?
Nothing. Your license is perpetual — the software continues to work and your project files remain accessible. Update renewals are optional. You never lose access to your models.
Can I share models with my team?
Yes. Project files are plain .dmm files. Share them via Git, a network share, or any file-transfer method your team already uses.
Does Luna Modeler support NoSQL databases?
Luna Modeler is built for relational databases. For MongoDB and other NoSQL databases, try Moon Modeler.
Disclaimer: Ideamerit s.r.o. is not affiliated with, endorsed by, or sponsored by dbdiagram.io or Holistics Software. The mention of dbdiagram.io is for comparison and informational purposes only.
