Prisma schema visualizer

What it does

Turn a Prisma schema into draggable UML and entity relationship diagrams with arranged SVG, reloadable layout JSON and Mermaid exports.

How to use it

1. Paste a single Prisma 7 schema or import a UTF-8 .prisma file, choose UML or ER view, then draw the schema.
2. For large schemas, use Analyze models to select models and optionally include their direct neighbors, then draw. Drag model cards, pan and zoom, then download the arranged SVG or save and restore layout JSON. Mermaid and schema JSON exports are also available.
3. Processing stays in your browser. No upload, database connection or sign-up.

Example

The example shows User and Post models, the Role enum and an optional author relationship: a User has zero or more posts; a Post has zero or one author.

Methodology

A pinned Prisma 7.10 WebAssembly engine validates the local schema; paired relation fields determine multiplicities. ELK lays out the graph in a second worker. React Flow provides draggable cards with shared vector geometry for SVG exports; layout JSON preserves nodes, edges and viewport. Configuration, defaults and comments are excluded from exports.

Limitations

Single-file Prisma 7 syntax; 250,000 characters / 1 MB import, 150 models and enums combined, 200 fields or enum values each, 5,000 total and 750 relationships. Parsing and automatic layout each stop after 15 seconds. Layout JSON imports are capped at 1 MB, depth 30 and coordinates ±100,000; restores must match the current diagram and view. SVG includes the entire arrangement; Mermaid does not retain manual positions. Views, composite types, ignored models/fields and Unsupported types are rejected. Logical associations, not database introspection: implicit junction tables are not drawn; indexes, referential actions, methods and inheritance are not shown. Mapped names and composite keys are in the model summary/JSON; enum values appear in UML and the summary. No generator, config file or migration is executed.

Automation

This tool runs in your browser. No upload API or MCP endpoint is available.