🆓 Free forever 🔒 100% client-side ⚡ Instant results

Database schema diff
in your browser

Paste two SQL CREATE TABLE dumps and see exactly what changed. Generate ready-to-run migration and rollback scripts for PostgreSQL, MySQL, SQLite, SQL Server, and Oracle.

✓ No signup ✓ No install ✓ Data stays private

What gets compared

SchemaLens understands real SQL structure, not just text lines. It detects semantic changes that manual diffing misses.

📋 Tables

Added, dropped, or renamed tables. See the full CREATE TABLE side-by-side with highlights.

🔤 Columns

New columns, removed columns, type changes, default values, nullable constraints, and collation changes.

🔑 Indexes & Constraints

Primary keys, foreign keys, unique constraints, and index additions or removals.

⚠️ Breaking Changes

Dropped columns, type narrowing, and NOT NULL additions are flagged with risk scores.

📝 Migration SQL

Get ALTER TABLE scripts in your target dialect, plus rollback SQL to reverse the change.

🔄 ORM Export

Export the diff as Prisma, Drizzle, TypeORM, or Sequelize schema snippets.

How it works

From paste to migration SQL in three steps.

1

Paste your schemas

Copy your CREATE TABLE dumps from any database or ORM into the before/after inputs. SchemaLens auto-detects the SQL dialect.

2

Review the visual diff

See tables, columns, indexes, and constraints color-coded by added, removed, or modified. Risky changes are highlighted.

3

Copy the migration

Grab the generated ALTER TABLE script, rollback SQL, or ORM export. Use it in your migration file or PR.

Supported SQL dialects

SchemaLens parses and generates migration SQL for the databases teams actually use.

PostgreSQL MySQL SQLite SQL Server Oracle

Diff schemas in your CI/CD pipeline

Stop breaking changes from reaching production. Add SchemaLens to your pull-request workflow in 60 seconds.

🐙 GitHub Actions

PR comments, Check Run status, and HTML report artifacts. Learn more →

🦊 GitLab CI

MR comments, smart skip, and breaking-change gates. Learn more →

🪣 Bitbucket Pipelines

PR comments and pipeline gates for schema changes. Learn more →

⚙️ Jenkins, CircleCI, Azure DevOps

Console reports, build descriptions, and artifact archiving. See all integrations →

- uses: aimadetools/race-kimi@v1.0.2
with:
  base-schema: ./schema/base.sql
  target-schema: ./schema/target.sql
  upload-report: true

Free, Pro, and Team

The web diff is free forever. Upgrade when you need power features or team workflows.

FeatureFreePro — $39 lifetimeTeam — $29/mo
Unlimited schema diffs
Migration + rollback SQL
Visual diff
ORM export
Export Markdown / PDF / JSON
Diff history & saved links
80+ micro-tools
Shared team workspace
Slack/Teams drift alerts

Frequently asked questions

Quick answers about how SchemaLens compares database schemas.

Is the database schema diff really free?

Yes. The browser-based diff, migration generation, rollback SQL, and ORM export are free forever with no account required. Pro adds exports, history, and micro-tools.

Do my schemas leave my browser?

No. The core diff runs entirely in your browser. Your SQL is never sent to our servers unless you explicitly use a server-side feature like the live GitHub PR diff viewer.

Can I compare schemas from live databases?

You can paste CREATE TABLE dumps from pg_dump, mysqldump, or any ORM. For live connections, use our GitHub Action or CLI in your CI/CD pipeline.

What counts as a breaking schema change?

Dropped columns or tables, type narrowing, adding NOT NULL without a default, and removing indexes are common breaking changes. SchemaLens flags each with a risk score.

How is this different from a text diff?

Text diff shows changed lines. SchemaLens parses SQL into tables, columns, and constraints and tells you what changed semantically — so a column rename looks like a rename, not a delete + add.

Compare your database schemas now

Paste two SQL schemas and see the diff in seconds. No signup, no install, no data sent to a server.