Now in public beta — free to use

Compare SQL schemas.
Generate migrations.
Zero setup.

Paste two CREATE TABLE dumps. Spot every difference instantly. Get ready-to-run ALTER TABLE scripts in PostgreSQL, MySQL, or SQLite — all in your browser.

No account required. No data leaves your device.

-- Schema A (Old) CREATE TABLE users ( id SERIAL PRIMARY KEY, name VARCHAR(100), email VARCHAR(100) );
-- Schema B (New) CREATE TABLE users ( id SERIAL PRIMARY KEY, name VARCHAR(100), email VARCHAR(255), created_at TIMESTAMP ); -- Generated Migration ALTER TABLE users ALTER COLUMN email TYPE VARCHAR(255); ALTER TABLE users ADD COLUMN created_at TIMESTAMP;

Why developers love SchemaLens

Stop squinting at text diffs. Get a semantic, visual comparison that understands your schema.

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Semantic Diff

Not a line-by-line text comparison. We understand tables, columns, types, defaults, indexes, and constraints.

Instant Migrations

Generate ALTER TABLE scripts in PostgreSQL, MySQL, or SQLite dialects. Copy, paste, deploy.

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100% Private

All processing happens in your browser. Your schemas never touch our servers. Perfect for sensitive data.

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Multi-Dialect

PostgreSQL, MySQL, MariaDB, SQLite support out of the box. More dialects coming based on demand.

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Export & Share

Download diffs as Markdown, PDF, or raw SQL. Share a link with your team for async review.

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Zero Install

No CLI to learn. No dependencies to install. No Docker image to pull. Open your browser and go.

How it works

From schema dumps to migration scripts in three simple steps.

Paste Schema A

Copy your old schema dump — from pg_dump, mysqldump, or your ORM — and paste it into the left pane.

Paste Schema B

Paste the new schema into the right pane. SchemaLens parses both instantly, understanding structure — not just text.

Review & Export

See every change highlighted. Generate migration SQL in your dialect. Export, share, or copy into your migration tool.

Free developer tools

Handy utilities that run in your browser. No signup required.

SQL Validator

Paste CREATE TABLE statements and get instant validation for PostgreSQL, MySQL, SQLite, and SQL Server.

Validate SQL

SQL Formatter

Beautify messy SQL queries with proper indentation, keyword casing, and syntax highlighting.

Format SQL
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Schema Diff

Compare two database schemas and generate migration scripts in seconds. Our flagship tool.

Compare Schemas

Simple, transparent pricing

Start free. Upgrade when you need more power.

Free

For side projects & quick checks

$0/mo
  • Diff up to 10 tables
  • Visual diff viewer
  • PostgreSQL, MySQL, SQLite
  • Local history (browser)
  • Migration generation
  • Export & share
Get Started

Team

For engineering teams

$29/mo
  • Everything in Pro
  • Shared team workspace
  • Slack notifications
  • Admin & user management
  • API access
  • SSO (coming soon)
Contact Sales

Stop writing migrations by hand.

Join 200+ developers who use SchemaLens to catch schema drift before it hits production.

Try SchemaLens Free

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