Free SQL Formatter
Format messy SQL into clean, readable queries using sql-formatter, the most widely used open-source SQL formatting library with over 750,000 weekly npm downloads. Supports 9 SQL dialects including MySQL, PostgreSQL, SQLite, Google BigQuery, SQL Server (T-SQL), Oracle (PL/SQL), Amazon Redshift, Apache Spark SQL, and standard SQL. Applies consistent formatting rules — uppercase keywords, proper indentation, aligned clauses, and logical line breaks — following best practices from style guides like Simon Holywell's SQL Style Guide. Handles complex queries with CTEs, subqueries, window functions, JOINs, and procedural blocks. Runs entirely in your browser via the sql-formatter TypeScript library, so your queries never leave your device. A free, private alternative to the SQL formatters built into paid tools like DataGrip, DBeaver, and Azure Data Studio.
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Why Format SQL Queries?
Well-formatted SQL is dramatically easier to read, debug, and review. When SQL comes from ORMs like Sequelize, Prisma, or SQLAlchemy, from query builders like Knex.js, or from application logs and slow query monitors, it is usually compressed into a single line or has wildly inconsistent spacing. A 200-character single-line query with nested subqueries is nearly impossible to debug. This tool applies consistent indentation, uppercase keywords, proper line breaks, and aligned clauses to transform any query into readable, structured SQL that follows industry best practices.
Consistent SQL formatting is not just about aesthetics — it directly impacts code review quality, team collaboration, and bug prevention. When every query in a codebase follows the same structure, reviewers can scan logic in seconds instead of minutes. Misplaced AND/OR conditions, accidental cross joins, missing GROUP BY columns, and incorrect WHERE clauses jump out immediately in well-formatted SQL. Teams that enforce consistent formatting report fewer bugs reaching production, shorter review cycles, and faster onboarding for new developers. SQL style guides from organizations like Mozilla, GitLab, and Meltano all emphasize formatting consistency as a foundational practice.
How the sql-formatter Library Works
This tool is powered by sql-formatter, the most widely used open-source SQL formatting library with over 750,000 weekly downloads on npm. Written in TypeScript, sql-formatter provides a dedicated parser for each of its 9 supported SQL dialects — Standard SQL (ANSI), MySQL, PostgreSQL, SQLite, Google BigQuery, SQL Server (Transact-SQL), Oracle (PL/SQL), Amazon Redshift, and Apache Spark SQL. Each parser understands the dialect-specific keywords, syntax extensions, and formatting conventions of its target database. MySQL LIMIT, PostgreSQL RETURNING and ON CONFLICT, BigQuery UNNEST and STRUCT, T-SQL TOP and MERGE, PL/SQL CONNECT BY — all are recognized and formatted correctly when you select the right dialect.
The library handles all major SQL constructs: Common Table Expressions (WITH clauses including recursive CTEs), nested subqueries at any depth, window functions with PARTITION BY and frame clauses, complex JOIN chains with multiple conditions, UNION/INTERSECT/EXCEPT operations, CASE/WHEN expressions, and procedural blocks like CREATE PROCEDURE with IF/ELSE and BEGIN/END. Formatting options include keyword casing (uppercase, lowercase, or preserve), indent width (spaces or tabs), indent style (standard or tabular alignment), line width limits, and dense operator spacing. The formatter can also be disabled for specific sections using inline comments, giving you precise control over the output.
SQL Formatting Best Practices and Style Guides
The most widely referenced SQL style guide is Simon Holywell's SQL Style Guide (sqlstyle.guide), which recommends uppercase reserved keywords, right-aligned "river" formatting where keywords align to create a uniform gap, and specific naming conventions for tables, columns, and aliases. The core rules that appear across nearly every SQL style guide include: uppercase SQL keywords (SELECT, FROM, WHERE, JOIN, GROUP BY, ORDER BY), lowercase for table and column names, each major clause starting on its own line at the same indentation level, consistent indentation for column lists and WHERE conditions, meaningful table aliases instead of cryptic single letters, and avoiding SELECT * in production queries.
This formatter enforces the structural rules automatically — consistent indentation, keyword casing, clause-per-line breaks, and aligned expressions — regardless of which specific style guide your team follows. Whether you prefer Simon Holywell's river style, Mozilla's 4-space indentation standard, or your own team conventions, running SQL through the formatter eliminates the inconsistency that makes queries hard to read and review. For teams adopting SQL formatting for the first time, start by picking an indent size (2 or 4 spaces) and keyword casing (uppercase is the most common convention), then format all existing queries to establish a baseline. The improvement in code review speed and query readability is immediate.
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How It Works
Paste your SQL query and select the dialect.
Click Format to beautify or Minify to compress.
Copy the formatted SQL to your clipboard.
Key Features
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Use Cases
Frequently Asked Questions
Is this SQL formatter completely free?
Yes, it is 100% free with no usage limits, no signup, and no per-query charges. IDE-based SQL formatters like those in DataGrip ($229/year) or paid database tools require licenses. Because this tool runs the sql-formatter library locally in your browser, there are no server costs and no restrictions on how many queries you format.
Is my SQL sent to a server or stored anywhere?
No. All formatting happens entirely inside your browser using JavaScript. Your SQL queries never leave your device — not even temporarily. There are no API calls, no cloud uploads, and no analytics on your query content. This makes it safe for formatting production queries, queries containing sensitive data, stored procedures with business logic, or any SQL you would not want a third party to see. You can verify this by checking the Network tab in DevTools while formatting.
What is sql-formatter and why is it used here?
sql-formatter is the most widely used open-source SQL formatting library, written in TypeScript and available on npm with over 750,000 weekly downloads. It is used by database tools, IDE extensions, documentation platforms, and developer utilities worldwide. The library provides a robust parser for each supported SQL dialect, ensuring that dialect-specific keywords and syntax are handled correctly. It is released under the MIT license and actively maintained. This tool runs sql-formatter directly in your browser, giving you the same formatting engine that powers many professional developer tools.
Which SQL dialects are supported?
The formatter supports 9 SQL dialects: Standard SQL (ANSI), MySQL, PostgreSQL, SQLite, Google BigQuery, SQL Server (Transact-SQL / T-SQL), Oracle (PL/SQL), Amazon Redshift, and Apache Spark SQL. Each dialect has its own parser that understands dialect-specific keywords and syntax — for example, MySQL LIMIT and SHOW, PostgreSQL RETURNING and ON CONFLICT, BigQuery UNNEST and STRUCT, T-SQL TOP and MERGE, and PL/SQL CONNECT BY. Select your dialect from the dropdown for the most accurate formatting.
Can it handle CTEs, subqueries, and window functions?
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.
Should SQL keywords be uppercase or lowercase?
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.
Is it safe to format production queries with this tool?
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.
How does this compare to the SQL formatter in DataGrip, DBeaver, or VS Code?
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.
Does it fix SQL errors or validate syntax?
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.
Can it format stored procedures and procedural SQL?
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.
What about parameterized queries with placeholders?
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.
What indentation options are available?
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.
Can it handle very long or complex queries?
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.
Does formatting change how my query executes?
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.
Why does SQL formatting matter for code reviews?
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.
What is the best SQL style guide to follow?
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.
Limitations
- Does not validate SQL syntax or check for errors — it formats whitespace only
- Does not execute queries or connect to databases
- Very vendor-specific syntax extensions may not format perfectly in all cases
- Does not add syntax highlighting or color coding to the output
- Does not rewrite or optimize query logic
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