How it works
- Paste, type, or open both versions from your device.
- Choose the precision and cleanup options that fit your content.
- Review additions and removals side-by-side or as a unified diff.
Useful features
- SQL syntax highlighting with precise change markers
- Unified and side-by-side SQL review
- Whitespace, case, and unchanged-line controls
- No database connection, credentials, or query execution
Common uses
- Comparing database migrations before deployment
- Reviewing stored procedure or view changes
- Auditing query, schema, and seed-script revisions
Tips for a cleaner comparison
- Keep clause and statement ordering visible.
- Use word precision for aliases, columns, and conditions.
- Remove embedded credentials before pasting any script.
How to compare two SQL scripts
Paste the current SQL script on the left and the proposed version on the right, or open two .sql files. Line precision shows added and removed statements, while word precision exposes changed table names, columns, joins, aliases, and predicates.
ComparLab treats SQL as source text. This makes the tool dialect-independent for MySQL, PostgreSQL, SQL Server, Oracle, SQLite, and other SQL scripts, but it does not interpret database state or prove that two queries are semantically equivalent.
Review SQL migrations and schemas
For a migration review, check CREATE, ALTER, and DROP statements together with indexes, constraints, defaults, and data backfills. Hide unchanged lines only after reviewing enough context to confirm which table or procedure each change affects.
- Confirm destructive DROP and TRUNCATE operations manually
- Check transaction boundaries and rollback statements
- Review changed nullability, defaults, indexes, and foreign keys
- Test the final migration in a safe database environment
SQL diff versus database comparison
This page compares SQL text such as queries, migrations, schemas, views, triggers, and stored procedures. It does not connect to a database or compare live tables, rows, execution plans, or database metadata.
Related comparison tools
Frequently asked questions
Does this SQL diff tool run queries?＋
No. It compares SQL as source text and never connects to a database.
Which SQL dialects work?＋
Any dialect can be compared as text, including MySQL, PostgreSQL, SQL Server, Oracle, and SQLite. The tool does not validate dialect-specific syntax.
Can I compare stored procedures and migrations?＋
Yes. Paste or open both script versions and use line or word precision to review the changes.
Is SQL uploaded?＋
No. It stays in memory in the current browser tab.
Choose the comparison that matches your data
Use Text Compare or Code Compare when every character and line should remain visible. Choose JSON, XML, or YAML when you want validation plus format-aware normalization, and use List Compare when the question is which values are missing, shared, or repeated. Selecting the matching tool helps remove harmless formatting noise without hiding meaningful changes.