Why format SQL?
Unformatted SQL — a single-line query with inconsistent spacing and mixed keyword cases — is significantly harder to read, debug, and maintain than properly formatted SQL. Comparing two versions of a query to spot differences is nearly impossible when both are single-line strings. Code review of database queries is more thorough when the reviewer can clearly see the structure of JOINs, WHERE conditions, and subqueries. Consistent formatting across a codebase reduces the cognitive load of reading queries written by different developers at different times.
The formatter takes messy, minified, or inconsistently formatted SQL and produces cleanly structured output with consistent indentation, keyword casing, and clause separation — in under a second.
Keyword casing
SQL keywords (SELECT, FROM, WHERE, JOIN, ORDER BY, etc.) are case-insensitive in all major databases — SELECT and select are equivalent. Conventions vary by team and organisation. UPPERCASE keywords are the most readable against lowercase identifiers and values, making the query structure immediately clear at a glance. This is the traditional convention and the formatter's default. Lowercase keywords are preferred by some teams who find all-caps visually aggressive and prefer consistent lowercase throughout. Preserve mode applies no transformation, useful when your team has already applied a convention you do not want to change.
How indentation works
The formatter applies indentation to create visual hierarchy: each major clause (SELECT, FROM, WHERE, JOIN, ORDER BY, GROUP BY) starts on a new line at zero indentation. AND and OR conditions within a WHERE clause are indented by one level, making the condition logic easy to parse. Column lists in SELECT are split one per line with indentation, making it easy to add, remove, or reorder columns. CASE...WHEN...THEN...ELSE...END blocks are indented to show their nesting clearly.
The minify option
The minify option does the opposite of formatting — it collapses all whitespace into a single-line query. This is useful when you need to embed SQL in a string in application code, store it in a configuration file with no multi-line support, or transmit it in a context where newlines would cause parsing issues. Minified SQL is also very slightly smaller for storage, though this rarely matters in practice.
Validation
The formatter performs basic SQL keyword detection — if the input does not contain any recognisable SQL keywords (SELECT, INSERT, UPDATE, DELETE, CREATE, ALTER, DROP, WITH, TRUNCATE), it shows a warning. This catches common mistakes like pasting non-SQL text into the input. It does not perform full SQL syntax validation — it cannot detect mismatched parentheses, invalid column references, or type mismatches, which require a connection to an actual database to validate.