Free SQL Formatter

Yes. The formatter correctly handles Common Table Expressions (WITH clauses), including recursive CTEs with multiple named subqueries. Nested subqueries in SELECT, FROM, WHERE, and HAVING clauses are properly indented to show nesting depth. Window functions with OVER, PARTITION BY, ORDER BY, and frame clauses (ROWS BETWEEN, RANGE BETWEEN) are formatted with clear structure. Complex queries combining all of these, such as a CTE feeding into a query with windowed aggregations and correlated subqueries, are formatted into readable, well-indented SQL.

Both conventions are widely used. The uppercase convention (SELECT, FROM, WHERE) is recommended by Simon Holywell's SQL Style Guide and is the traditional standard, it visually separates keywords from table and column names, making queries easier to scan. The lowercase convention argues that modern editors provide syntax highlighting, making casing redundant, and that lowercase is easier to type. The important thing is consistency. This formatter defaults to uppercase keywords, which is the most common convention, but the key benefit is that every query gets the same treatment regardless of how it was originally written.

Yes. The formatter only changes whitespace, it adds indentation, line breaks, and adjusts keyword casing. It does not modify your SQL logic, table names, column references, values, or query structure in any way. The output query is semantically identical to the input. Additionally, since all processing happens locally in your browser, your production queries containing sensitive table names, business logic, or data values are never transmitted anywhere. It is safe for formatting queries from any environment, development, staging, or production.

IDE-based formatters like those in JetBrains DataGrip, DBeaver, and Azure Data Studio are deeply integrated into their editors and can leverage database schema awareness for additional intelligence. However, they require installing and configuring the IDE, and DataGrip requires a paid license ($229/year). This tool provides the same core formatting, indentation, keyword casing, clause alignment, instantly in your browser with zero setup. It is ideal for quick formatting tasks, for sharing formatted SQL with teammates who use different editors, or for anyone who does not want to install a full IDE just to clean up a query. The sql-formatter library itself powers many VS Code extensions and web-based database tools.

No. This tool is a whitespace formatter, not a SQL linter or validator. It reformats the spacing, indentation, and keyword casing of your SQL without checking whether the query is syntactically correct or will execute successfully. If your SQL has a missing comma, an unmatched parenthesis, or references a nonexistent table, the formatter will still format it, the output will be more readable but will contain the same errors. For syntax validation, use your database client, an IDE with SQL intelligence, or a dedicated SQL linter.

Yes. The formatter handles procedural SQL constructs including CREATE PROCEDURE, CREATE FUNCTION, BEGIN/END blocks, IF/ELSE/ELSEIF conditionals, WHILE and LOOP statements, DECLARE variable declarations, SET assignments, and CASE/WHEN expressions. For PL/SQL, it also handles Oracle-specific constructs like EXCEPTION blocks and cursor declarations. For T-SQL, it supports TRY/CATCH, PRINT, and other SQL Server procedural extensions. The key is to select the correct dialect so the parser recognizes the procedural keywords specific to your database.

The sql-formatter library supports parameterized queries with both positional and named placeholders. Positional placeholders like ? (used in MySQL, SQLite, and JDBC) and numbered placeholders like $1, $2 (used in PostgreSQL) are preserved during formatting. Named placeholders like :name, @name, and :variable used in Oracle, SQL Server, and various ORMs are also handled correctly. The formatter treats placeholders as values and does not alter them, so your parameterized queries maintain their placeholder structure after formatting.

You can choose between 2-space and 4-space indentation. The sql-formatter library also supports multiple indent styles: "standard" indentation where clauses are indented under their parent keywords, and "tabular" styles (tabularLeft and tabularRight) that align keywords to create a uniform visual column, similar to the "river" formatting recommended by some SQL style guides where keywords align on the right and values align on the left. The default standard style with 2 or 4 spaces works well for most teams and matches the conventions used in popular SQL style guides.

Yes. Because the formatting runs locally in your browser, there is no query size limit imposed by a server. The sql-formatter library processes queries of any length, including complex analytical queries with dozens of CTEs, deeply nested subqueries, large UNION chains, and multi-hundred-line stored procedures. Performance depends on your device, but modern browsers handle even very large queries (thousands of lines) in under a second. For extremely large SQL files, consider formatting individual queries rather than the entire file at once.

No. SQL formatting is purely cosmetic, it only changes whitespace characters (spaces, tabs, newlines) and optionally keyword casing. The database engine ignores whitespace when parsing SQL, so a formatted query and its minified equivalent produce identical execution plans and return identical results. The only change is readability for humans. This is the same principle behind code formatters like Prettier for JavaScript or Black for Python, they change how code looks without changing what it does.

Consistently formatted SQL makes code reviews dramatically faster and more effective. When every query follows the same indentation, keyword casing, and clause structure, reviewers can scan the logic in seconds instead of spending time mentally parsing inconsistent formatting. Misplaced AND/OR conditions, accidental cross joins, missing GROUP BY columns, and incorrect WHERE clauses are far easier to spot in well-formatted SQL. Teams that enforce consistent SQL formatting through tools like this report fewer bugs reaching production, shorter review cycles, and faster onboarding for new developers who can read any query in the codebase without adjusting to different personal styles.

The most widely referenced SQL style guide is Simon Holywell's SQL Style Guide (sqlstyle.guide), which recommends uppercase keywords, right-aligned river formatting, and specific naming conventions. Mozilla, Meltano, and GitLab also publish SQL style guides with similar principles. The common rules across most guides include: uppercase reserved keywords (SELECT, FROM, WHERE), lowercase for table and column names, each major clause on its own line, consistent indentation for column lists and conditions, meaningful table aliases instead of single letters, and no SELECT * in production queries. This formatter enforces the structural rules, indentation, keyword casing, and line breaks, automatically, regardless of which style guide your team follows.