Version 0.9.15
Free Forever for Education

ERD Tool Built
for Developers.

Full relation control, Git-native collaboration, live database sync, and migration generation - in an 8 MB native app. No DBA knowledge required.

Everything a Developer Needs in an ERD Tool

Diagram control that rivals enterprise tools. Git-native workflow. Live database sync. All in a lightweight native app.

Relation as First-Class Citizen

Full routing control, bend points, self-reference, and advanced snapping. The only lightweight ERD tool with first-class citizen relation support.

Git-Native Collaboration

Clone to offline ERD, commit, team pulls. A long-lived ERD that evolves with your codebase - not locked in a cloud service.

Developer-First Simplicity

Drag to create a relation. Opinionated defaults - snake_case, auto FK naming, auto junction table. No DBA knowledge required.

Live Database Sync

Connects to MySQL and PostgreSQL, reads the real schema, and keeps your ERD in sync with actual database state.

Migration Generation

Compares your ERD to the live database and generates the exact SQL diff - nothing more, nothing less.

Local-First, Data Transparent

Plain JSON files in ~/schemity/ - readable, backupable, portable. You own your data completely. No cloud dependency.

8 MB Bundle

No JVM, no Electron, no Chromium. Built with Native WebView and Rust - fast to download, instant to launch.

Works Everywhere

Fully offline, air-gapped, behind VPN. No internet connection required - ever.

Diagram Control That Rivals Enterprise Tools

Full relation routing, smart defaults, and a visual editor that stays out of your way - so you can focus on your schema, not the tool.

Rapid Prototyping demo

Rapid Prototyping

Sketch your domain in seconds. Go from concept to concrete entities before the idea fades.

Smart Relationships demo

Smart Relationships

Model how concepts in your domain relate to each other - one-to-many, many-to-many - with simple drag-and-drop. No manual wiring needed.

Flexible Relationship Lines demo

Flexible Relationship Lines

Arrange your domain model the way you think about it, not the way the layout forces you. Lines adapt and reroute automatically.

Check Constraints as Documentation demo

Check Constraints as Documentation

Encode domain rules as constraints. They become both enforceable logic and living documentation - referenceable directly in default values.

Custom Entity Colors demo

Custom Entity Colors

Group domain concepts visually. Color-code bounded contexts and related entities for instant clarity at a glance.

Clear Unique Together demo

Clear Unique Together

Instantly distinguish between single-field unique constraints and composite unique together groups at a glance.

Safe Migration Workflow demo

Safe Migration Workflow

Domain changes are intentional. Every schema change requires explicit migration confirmation - no accidental alterations to your database.

Multiple Tabs demo

Multiple Tabs

Work across multiple tabs simultaneously with quick number-key navigation to stay focused and organized.

Multiple Schemas demo

Multiple Schemas (PostgreSQL)

Model across PostgreSQL schemas to reflect domain boundaries - not just the public schema.

From ERD to Running Database

Design visually, sync with your live database, generate the SQL diff, and commit alongside your code.

1

Design Your ERD

Drag to create entities and relations. Opinionated defaults handle snake_case naming, auto FK, and junction tables. Start from scratch or sync from a live database.

2

Generate SQL Diff

Schemity compares your ERD to the live database and generates the exact SQL migration to close the gap - nothing more, nothing less.

3

Commit & Collaborate

Your ERD lives as plain JSON files alongside your code. Commit, push, and let teammates pull - Git handles the rest.

Native on Every Platform

Experience seamless performance and native feel across all major operating systems.

The ERD Tool Built for Developers.

Full relation control. Git-native. Live database sync. 8 MB. Download Schemity and get started in seconds.