Best AI Database Schema Generators and ER Diagram Tools (2026)

An AI database schema generator turns a plain-language description of an application into tables, keys and relationships, usually drawn as an ER diagram you can edit. In 2026 the tools differ less in drafting than in what comes next: where the schema lives, who edits it and what code it exports. Disclosure: Jishu Labs, which publishes this blog, makes Kozo, one of the six tools compared here.

Prices and features below come from each vendor's own pages as of October 27, 2026. Plans change often, so check before you buy.

Which AI database schema generator should you use in 2026?

Use dbdiagram.io if your team keeps schemas as DBML code, ChartDB if you need open source or self-hosting, DrawSQL for diagrams several people edit at once, Supabase's AI Assistant if your database already runs on Supabase, Eraser for diagrams drawn from documents, and Kozo for a new Postgres schema exported straight into ORM models and migrations.

What is dbdiagram.io best for?

dbdiagram.io is best for teams that want their schema written as code. Built by Holistics, it draws ER diagrams from DBML, an open-source markup language for database structures, and its AI Assistant (Beta) turns chat prompts into DBML changes that you review in a diff viewer before accepting them.

Per its documentation, the Assistant also suggests data types, indexes and constraints and converts schemas between database systems. dbdiagram.io can also import an existing database or SQL dump and generate the SQL to create your tables.

Free allows 10 diagrams without AI. Personal Pro is $8 a month with 1,000,000 AI tokens a month, and Team is $75 a month for three editors, both billed annually (as of October 2026).

Choose it over Kozo when your team reviews schema changes as DBML in Git, or you mainly need to document an existing database.

What is ChartDB best for?

ChartDB is best for teams that want an open-source ER diagram tool they can host themselves. It is published on GitHub under the AGPL-3.0 licence, imports an existing schema with a single query, and its AI generator turns a description into an editable ER diagram.

The ChartDB repository lists PostgreSQL, MySQL, SQL Server, MariaDB, SQLite, CockroachDB and ClickHouse. Its AI export writes DDL in the dialect you choose; self-hosted, it needs your own OpenAI API key or a compatible endpoint.

On ChartDB's hosted plans, Free is limited to 10 tables, Pro is US$25 a month, and Teams starts at US$59 for three users with real-time collaboration and an AI Assistant (Basic), both on yearly billing (as of October 2026).

Choose it over Kozo when the schema must stay on your own servers without an enterprise contract, you use SQL Server, SQLite or ClickHouse, or you are diagramming a live database.

What is DrawSQL best for?

DrawSQL is best for teams that design schemas together in a shared visual editor. Its built-in AI generates tables and relationships from a text description, reviews a schema for issues such as missing indexes and inconsistent naming, and shows proposed changes as a diff before you apply them.

Per the DrawSQL site, diagrams cover MySQL, PostgreSQL, SQL Server and MariaDB, exports include SQL DDL, Laravel migrations and JSON, and teams can attach discussion threads to tables and return to earlier versions.

Free allows unlimited public diagrams of up to 15 tables, without AI. Starter is $19 a month for 10 private diagrams and 500 AI credits a month; real-time multiplayer starts on Growth at $59 a month for up to five users (as of October 2026).

Choose it over Kozo when several people edit one diagram at once, you want comments and version history on the schema, or you build on Laravel.

Can Supabase's AI Assistant design a database schema?

Yes, if your project already runs on Supabase. The Supabase AI Assistant is built into the Supabase Dashboard. When you describe something new, Supabase says it shows how to structure the database and generates the SQL to set it up, and it writes and edits row-level security policies using your existing schema as context.

Supabase's feature page lists the Assistant as a public alpha; self-hosted Supabase needs an OpenAI API key for it. In its December 2024 launch post, Supabase said only schema structure, not data, is sent to the model. Studio also has a generally available Visual Schema Designer for drag-and-drop design.

The pricing page does not list the Assistant separately. Supabase's Free plan allows two active projects and pauses them after a week of inactivity; Pro starts at $25 a month (as of October 2026).

Choose it over Kozo when the database already lives on Supabase and you want the AI working against the real project instead of a separate design file.

What is Eraser's AI ERD generator best for?

Eraser is best for ER diagrams that belong in design documents and architecture reviews. Its AI ERD generator accepts plain English, a code snippet such as an existing SQL or ORM schema, or pasted requirements and transcripts, and draws a diagram you edit as diagram-as-code or visually.

The ERD generator page does not mention SQL, DDL or migration output, so treat the result as a diagram rather than a deployable schema. Free includes 3 files and 3 AI credits; Business is $45 per member a month billed annually, or $60 monthly, with 100 AI credits a month (as of October 2026).

Choose it over Kozo when the deliverable is a diagram for people to discuss, not SQL or ORM models to run.

What is Kozo best for, and what does it not do?

Kozo is best for developers starting a new Postgres-backed application who want the schema exported straight into code. Describe your app in plain English and Kozo designs a normalized, indexed, migration-ready Postgres schema with a live ER diagram in seconds. Exports cover PostgreSQL, MySQL, Prisma, Drizzle, SQLAlchemy and JSON Schema.

Pro, at $15 a month, adds a health score for normalization, integrity and performance with specific findings, reversible up and down migrations, seed data and Supabase row-level security policies. Free covers generation, the live ER diagram and core exports (as of October 2026). Pasted DDL can be diagrammed and audited too.

Its limitations are real:

• It is a young product, with a shorter track record than the established tools here.
• No live database connection. Kozo works from descriptions and pasted DDL only, so it cannot import from or sync with a running database as ChartDB can.
• No real-time co-editing. Its plans list no multiplayer editing (DrawSQL Growth and ChartDB Teams have it) and no comment threads.
• Six schema export targets: PostgreSQL, MySQL, Prisma, Drizzle, SQLAlchemy and JSON Schema. No SQL Server, SQLite or ClickHouse.
• Self-hosting needs Enterprise. Kozo is not open source, self-hosting is on the custom-priced Enterprise plan, and health scoring, migrations, seed data and RLS export are Pro-only.

Choose Kozo when you are starting from an idea, not an existing database, and want Postgres DDL, ORM models, migrations and seed data from one design at kozo.jishulabs.com.

How do you choose an AI schema generator?

Choose an AI schema generator by where the schema has to end up, not by how good the first draft looks. Every tool here can draft a schema or diagram from a short description; they differ in output (DBML, SQL, ORM models, migrations or only a diagram), in whether they read a live database, and in hosting.

• Code or picture? Eraser produces diagrams. dbdiagram.io, ChartDB, DrawSQL and Kozo export SQL; DrawSQL adds Laravel migrations, and Kozo adds Prisma, Drizzle and SQLAlchemy models and migrations.
• Existing database? ChartDB and dbdiagram.io read from existing databases, Supabase's Assistant works inside your project, and DrawSQL and Kozo take pasted CREATE TABLE statements.
• Self-hosting? ChartDB is open source and self-hostable for free, and self-hosted Supabase runs the Assistant with your own OpenAI key. Kozo offers self-hosting on Enterprise only.

PostgreSQL's constraints documentation explains why foreign keys are not indexed for you. For the concepts behind these checks, see what an ER diagram is, database normalization and schema migrations.