Both sides use one fail-closed model
Unsupported DDL fails before comparison so missing model support cannot masquerade as a removed declaration.
- Input
- SQL
- Dialects
- 4 explicit
- Runtime
- Browser
Compare supported CREATE TABLE declarations
Extract the same narrow schema model from two DDL inputs and compare their tables, columns, and foreign keys.
Local processingNo sign-upNever executed
Compare schemas
Inputs stay in this browser tab. Parser-heavy work uses a tighter 256 KiB safety cap.
Schema change report
No result is placed in a URL, account, API, or remote log.
What this tool does
Bounded, explicit-dialect processing
A structural DDL difference is not a safe migration plan. Data compatibility, locks, dependencies, defaults, indexes, privileges, and engine behavior remain outside this comparison.
Migration safety requires the target database
The report explicitly avoids claims about destructive changes, casts, backfills, locks, or deploy ordering.
The parser runs locally under byte, statement, AST-node, depth, row, column, diagnostic, and output limits. It never connects to a database or resolves files and URLs.
Questions and answers
Related SQL tools
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