MOLT Verify is a data validation tool designed by Cockroach Labs to ensure the accuracy of database migrations. It compares a source database against a target CockroachDB cluster at multiple levels, including schema and row-level data validation. The tool performs checks such as table verification, column definition verification, and row data verification to catch any discrepancies. MOLT Verify supports verifying data from PostgreSQL or MySQL sources against a CockroachDB cluster and is provided as a standalone CLI tool. It offers key benefits like reducing the risk of data corruption, providing faster automated data validation, and validating beyond row counts. The tool's architecture integrates with CockroachDB and source databases using standard database connections, abstraction layers, and schema mapping assumptions. MOLT Verify acts as a safety net in the migration workflow, dramatically reducing the risk of data corruption or loss during large-scale migrations. To use MOLT Verify effectively, consider running verification at key points in the migration, minimizing changes for the final verification, tuning concurrency and batching, and using best practices like continuous replication and filtering out false mismatches.