SQL Formatter and Validator
Format, beautify, or minify SQL queries instantly. Supports MySQL, PostgreSQL, SQLite, and SQL Server with syntax highlighting and structural validation. Free, no signup, browser-only.
Quick examples:
How SQL formatting improves query readability
Formatted SQL is easier to read because each clause starts on a new line at a predictable indentation level. When SELECT, FROM, WHERE, GROUP BY, and ORDER BY all start at the left margin, and JOIN conditions are indented one level beneath the JOIN keyword, the structure of the query becomes immediately visible without scanning for keywords embedded in long lines.
Consistent formatting also makes code review faster. A reviewer can scan vertically down the clause list to understand what a query does before reading individual conditions. Unformatted queries written as single-line strings in application code often contain logic errors that are invisible until formatted. Tools like a JSON formatter and a regex tester serve the same purpose for other data formats: surface structure that inline strings hide.
MySQL, PostgreSQL, SQLite, and SQL Server formatting differences
All four major SQL dialects share the same core syntax for SELECT, JOIN, WHERE, GROUP BY, and ORDER BY. The differences lie in specific functions, quoting conventions, and proprietary extensions. MySQL uses backticks for identifier quoting, PostgreSQL uses double quotes, and SQL Server uses square brackets. The formatter above uses the dialect selector to apply the correct quoting style when it detects identifier patterns in your query.
PostgreSQL-specific syntax like date_trunc(), ILIKE, and RETURNING are formatted the same way as standard SQL keywords. SQL Server TOP n syntax is placed on the SELECT line. Load the sample queries from the dropdown in the tool above to see how CTEs, JOINs, aggregations, and subqueries are formatted. When working with JSON columns returned by PostgreSQL or MySQL 5.7+, a JSON formatter is useful for inspecting those column values.
When to minify SQL and what the formatter removes
Minified SQL is useful when embedding queries in application config files, ORM definitions, or JSON payloads where multi-line strings are awkward. Minification collapses all whitespace to single spaces, removes line breaks, and strips comments. The result is a valid, compact query that executes identically to the formatted version.
String literals inside single quotes are preserved exactly during minification, including any whitespace inside them. A string value like 'hello world' stays as-is; only whitespace outside of quoted strings and comments is collapsed. The diff view in the tool above shows a side-by-side comparison of the original and output so you can verify nothing unexpected changed. If your workflow involves encoded API payloads alongside your SQL, the Base64 encoder and the URL encoder are useful companions.
Frequently asked questions about SQL formatting and beautification
What is a SQL formatter?
A SQL formatter takes unformatted or minified SQL queries and rewrites them with consistent indentation, line breaks, and keyword casing. It makes queries easier to read, debug, and review by placing each clause like SELECT, FROM, WHERE, and JOIN on its own line with proper indentation.
How do I format a SQL query online?
Paste your SQL into the input field above and click Format SQL or press Ctrl+Enter. The formatter adds line breaks at each major clause, indents subqueries and JOIN conditions, and optionally uppercases all keywords. The formatted result appears in the output panel on the right.
What SQL dialects does this formatter support?
The formatter supports MySQL, PostgreSQL, SQLite, and SQL Server. Select your dialect from the dropdown before formatting. Dialect selection affects how the formatter handles dialect-specific syntax and quote styles, though the core formatting logic applies to all dialects.
What is SQL minification?
SQL minification removes all unnecessary whitespace, line breaks, and comments from a SQL query to produce the most compact version possible. Minified SQL is useful when embedding queries in application code or config files where whitespace adds no value and only increases file size.
Does the formatter validate SQL syntax?
Yes. The formatter checks for common structural errors including unbalanced parentheses and unclosed string literals. If an error is detected, a warning is shown above the output. For full syntax validation against a specific database engine, run the query against a live database connection.
Should SQL keywords be uppercase or lowercase?
SQL keywords are case-insensitive, but the convention in most style guides is uppercase for keywords (SELECT, FROM, WHERE) and lowercase for identifiers (table names, column names). Uppercase keywords visually separate the structure of the query from the data references. The formatter uppercases keywords by default but this can be disabled.
How do I indent SQL subqueries?
Subqueries inside parentheses are automatically indented one level deeper than the surrounding query. The formatter detects opening parentheses after IN, FROM, EXISTS, and other keywords and increases indentation for the enclosed query. Closing parentheses are dedented back to the correct level.
What is the difference between 2-space and 4-space SQL indentation?
Both 2-space and 4-space indentation are valid. 4-space indentation is common in SQL style guides for making nested subqueries visually distinct at multiple levels. 2-space indentation saves horizontal space in deeply nested queries. Choose based on your team style guide or personal preference.
Can I use this SQL formatter for CTEs and window functions?
Yes. The formatter handles WITH clauses (CTEs), window functions using OVER, and PARTITION BY. Each CTE in a WITH clause is placed on its own line with the body indented. Window function clauses are formatted inline. Load the CTE sample query from the dropdown above to see an example.
Is my SQL query sent to a server?
No. All formatting, minification, validation, and syntax highlighting run entirely in your browser using JavaScript. Your SQL is never sent to any server. This makes the tool safe to use with sensitive schema names, table names, or query structures from production databases.