SQL Schema Diff Checker
Compare two CREATE TABLE statements and list added, removed and changed columns.
Runs in your browser. Nothing is uploaded — your input is processed on this device and discarded when you close the tab.
SQL Schema Diff Checker
How to use this tool
- Paste the old definition in the first box and the new one in the second.
- Press Compare to see added, removed and changed columns.
- Review removals carefully — dropping a column can lose data; a diff list is not a migration script.
Worked example
Old: users (id INT, name VARCHAR(50)). New: the same plus email VARCHAR(100). The result reports Added: email, Removed: none, Changed: none.
What this tool does not do / Limits
The parser handles simple column lists only. It skips constraints and keys, ignores indexes, and does not generate migration SQL or check data compatibility — a type change listed as Changed may still lose data.
Frequently asked questions
Does it handle multiple tables?
No — compare one table at a time, so each diff stays readable.
Does it write a migration?
No. It only reports the difference; you write and test the migration yourself.
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