SQL Diff

SQL Diff

Updated August 21, 2026

Compare two SQL queries online. Format both, then diff. Whitespace and keyword case do not count as changes. Free SQL compare tool.

Dialect

Left SQL

0 lines · 0 chars

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Right SQL
 
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Features
 
  •  Format both queries with the same dialect before comparing
  •  Ignore keyword case and indent noise
  •  Line-level added and removed hunks
  •  Works for SELECT, INSERT, DDL, and scripts
  •  Nothing is uploaded
 
Common Use Cases
 
  •  See what changed between two versions of a report query
  •  Compare ORM SQL before and after an upgrade
  •  Check that a formatter-only change is whitespace
  •  Review a migration script against last week’s copy
 
Formatted diff, not EXPLAIN
 
Both sides are pretty-printed with the same dialect and uppercase keywords, then compared line by line. That hides indent-only edits. It does not prove two queries return the same rows. Semantically equal SQL (a = 1 AND b = 2 vs the reverse) can still show a diff.
 
Examples
 
 Valid - Same query, different wrap
 
select id from t; vs SELECT id FROM t;
 Valid - Real change
 
WHERE active = true vs WHERE active = false
  
Frequently Asked Questions
 
 
Why is there no diff after I change spaces?
 
Both queries are formatted first. Indent and keyword case are normalized on purpose.
 
Can I diff two files of 10k lines?
 
The LCS diff is fine for typical queries. Multi-megabyte scripts may freeze the tab. Use git diff locally for those.
  
Related Tools
 
SQL Formatter
 
Pretty-print one query
 
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SQL Validator
 
Parse each side first
 
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Text Diff
 
Raw string compare
 
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 Tips
 
  •  If parse fails, fix quotes on that side first. Diff needs both queries to format.