How to Format SQL Online — Free SQL Beautifier (Postgres, MySQL, SQLite)

Why formatting matters for SQL specifically

A 20-line SQL query is often harder to understand than a 200-line function in most languages. Joins across three tables, filters in WHERE, grouping, window functions, subqueries — when these are jammed on one line with inconsistent capitalization, even the author needs a minute to re-parse. Consistent formatting turns that into "read once, understand."

What the SQL formatter does

• Uppercases reserved keywords — SELECT, FROM, WHERE, JOIN, ON
• Aligns clauses vertically — one keyword per line, easy to scan
• Indents nested subqueries consistently
• Breaks long SELECT lists one column per line when they exceed a threshold
• Preserves your exact string literals and comments — no accidental semantic changes

Example transformation

-- Before
select u.id, u.email, count(o.id) as orders from users u left join orders o on o.user_id = u.id where u.created_at > '2025-01-01' group by u.id, u.email having count(o.id) > 5 order by orders desc;

-- After
SELECT
  u.id,
  u.email,
  COUNT(o.id) AS orders
FROM users u
LEFT JOIN orders o ON o.user_id = u.id
WHERE u.created_at > '2025-01-01'
GROUP BY u.id, u.email
HAVING COUNT(o.id) > 5
ORDER BY orders DESC;

Dialect support

Dialect	Notes
Postgres	Default; supports CTEs, window functions, arrays, JSONB operators
MySQL	Backtick identifiers handled; USE statements recognized
SQLite	Concise syntax; bare-bones but complete
SQL Server (T-SQL)	Square-bracket identifiers; TOP instead of LIMIT
MariaDB	MySQL-compatible; extra analytical functions

Pair with explain plans

Formatting doesn't make a query fast — it makes it readable. For actual performance work, run EXPLAIN ANALYZE (Postgres) or EXPLAIN (MySQL) and inspect the plan. A formatted query is easier to pattern-match against indexing advice.

Related tools

For JSONB and JSON columns in Postgres, pretty-print the JSON with JSON formatter. For comparing two query versions side-by-side (e.g., before and after refactoring), diff checker highlights what changed.