🚀 TypeORM Schema Diff

Compare TypeORM Schemas Without the CLI

Paste two TypeORM entity definitions or generated SQL and get an instant visual diff. See entities, columns, relations, and indexes that changed — then generate the migration SQL. No npx typeorm required.

How it works

SchemaLens parses your TypeORM schema (decorator entities or generated SQL), compares it against another version, and shows you exactly what changed — just like typeorm migration:generate, but in your browser with a visual UI.

📋 Entity Diff

See which entities were added, removed, or renamed. Catch accidental entity deletions before they drop tables.

🔤 Column Changes

Spot type changes, nullable vs non-nullable updates, default value changes, and decorator modifications at a glance.

🔗 Relation Detection

Visualize added or removed @ManyToOne, @OneToMany, and @ManyToMany relations that affect your data integrity.

📊 Index & Unique

Compare @Index, @Unique, and composite index declarations. Missing indexes can kill query performance.

📝 Generate SQL

Export migration scripts in PostgreSQL, MySQL, SQLite, SQL Server, or Oracle dialects — ready to run with typeorm migration:run.

🔗 Shareable Links

Share a diff URL with your team or paste it in a PR review. No screenshots, no copy-paste needed.

SchemaLens vs TypeORM CLI

Both tools compare schemas. SchemaLens adds a visual layer and works without installing anything.

Feature SchemaLens typeorm migration:generate TypeORM Studio
Browser-based (no install) ✅ Yes ❌ CLI only ❌ CLI + local DB
Visual diff UI ✅ Yes ❌ SQL files ❌ No diff
Compare two arbitrary schemas ✅ Paste any two ✅ Yes ❌ No
Multi-dialect SQL output ✅ 5 dialects ❌ Target only ❌ No
Shareable diff URLs ✅ Yes ❌ No ❌ No
Breaking change warnings ✅ Yes ❌ No ❌ No
Cross-dialect migrations ✅ Yes ❌ No ❌ No
View/edit live data ❌ No ❌ No ✅ Yes

When to use SchemaLens with TypeORM

SchemaLens complements your TypeORM workflow. Use it when you need speed, shareability, or a visual review layer.

🔍

Code Reviews

Paste the before/after schema into SchemaLens and drop the shareable link in your PR. Reviewers see exactly what changed without running typeorm migration:generate locally.

🏭

Staging vs Production Checks

Export your staging and production schemas, paste them both, and verify the diff before promoting to prod. Catch drift that migrations didn't account for.

👥

Team Collaboration

Not everyone on your team has TypeORM installed or knows CLI flags. SchemaLens lets designers, PMs, and junior devs review schema changes in a familiar visual interface.

🔀

Cross-Dialect Migrations

Moving from PostgreSQL to MySQL? SchemaLens shows you the semantic differences and generates the target dialect's migration SQL — something TypeORM CLI can't do across databases.

Works with your TypeORM workflow

SchemaLens is not a replacement for TypeORM migrations. It's a visual companion for the moments when you need to see the diff, share it, or review it quickly.

1️⃣ Export your schema

Copy your entity .ts files or run typeorm migration:generate and grab the generated SQL. Paste it into SchemaLens.

2️⃣ Paste the target schema

Paste the older (or newer) version you want to compare against. SchemaLens parses both automatically.

3️⃣ Review the diff

Visual highlights show added entities, removed columns, type changes, and index modifications. Breaking changes are flagged in red.

4️⃣ Generate & share

Export migration SQL in your target dialect, or copy a shareable link to paste in Slack, Jira, or your PR description.

Diff your TypeORM schema now

No signup. No install. Paste two schemas and see the diff in 5 seconds.

Start Comparing →