PostgreSQL SQL Validator — Check Postgres Syntax Online
Validate your PostgreSQL queries before running them. This validator is preconfigured for PostgreSQL dialect, flagging syntax that is valid in other databases but fails in Postgres — and vice versa. It recognizes Postgres-specific features like :: type casting, ILIKE for case-insensitive matching, RETURNING clauses on INSERT/UPDATE/DELETE, and array syntax. It also flags SQL Server syntax like TOP that does not work in PostgreSQL. Everything runs in your browser.
What This Tool Does
Validates PostgreSQL SQL syntax in your browser including CTEs, window functions, RETURNING clauses, and PostgreSQL-specific data types — with precise error locations.
Who This Is For
- PostgreSQL and Supabase developers verifying query syntax before running migrations
- Backend engineers writing complex analytics queries with window functions or CTEs
- Data engineers building PostgreSQL pipelines who want to validate SQL scripts programmatically
- Anyone learning PostgreSQL who wants immediate syntax feedback
Example: Input: SELECT id, ROW_NUMBER() OVER PARTITION BY dept ORDER BY salary FROM employees → Output: Error: Missing parentheses around PARTITION BY clause in window function — with the exact token identified
PostgreSQL-Specific Validation
The PostgreSQL validator mode enables additional checks beyond generic SQL validation:
::type casting — Recognized as valid (e.g.,column::integer). Flagged as invalid when dialect is MySQL or T-SQL.ILIKE— Case-insensitive LIKE is valid in PostgreSQL. Flagged as unsupported in MySQL, T-SQL, and SQLite.RETURNING— The RETURNING clause on INSERT, UPDATE, and DELETE is valid in PostgreSQL. Flagged as unsupported in MySQL.TOP N— Flagged as invalid in PostgreSQL. UseLIMITinstead.- Dollar-quoted strings — PostgreSQL's
$$...$$string syntax is handled by the parser.
Common PostgreSQL Syntax Pitfalls
Developers moving to PostgreSQL from other databases frequently encounter these issues:
- String quoting — PostgreSQL uses single quotes for strings and double quotes for identifiers.
WHERE name = "John"looks for a column called "John", not the string 'John'. - Boolean handling — PostgreSQL has a native
BOOLEANtype. UseTRUEandFALSE, not1and0. - Type strictness — PostgreSQL is stricter about implicit type conversions than MySQL. You may need explicit casts.
- Case sensitivity — Unquoted identifiers are folded to lowercase.
SELECT * FROM Usersqueries theuserstable. Use"Users"to preserve case.
PostgreSQL Version Compatibility
The validator checks against widely supported PostgreSQL features. Some newer syntax (e.g., MERGE added in PostgreSQL 15, JSON_TABLE in 17) may not be fully validated. If you are targeting a specific PostgreSQL version, test your queries in a development environment in addition to using this tool.
🔒 Privacy & Security
Your SQL never leaves your browser. There is no server — all parsing, validation, formatting, and explanation happens in JavaScript running locally on your device. This means your table names, column names, query logic, and data patterns are never transmitted anywhere. You can disconnect from the internet after loading this page and the tool still works.
Frequently Asked Questions
SQL Tool Suite
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