SQL Formatter

Which words move to their own line

The tokenizer skips whitespace, keeps a quoted string together (a doubled quote inside quotes is still part of the token), keeps a -- comment through the end of the line, and treats parenthesis and comma as their own tokens. Other characters gather into words. Format then uppercases a word only when the uppercase form is in a fixed set: SELECT, FROM, WHERE, AND, OR, JOIN, the join directions, ON, GROUP, BY, ORDER, HAVING, LIMIT, OFFSET, INSERT, INTO, VALUES, UPDATE, SET, DELETE, CREATE, TABLE, ALTER, DROP, AS, DISTINCT, UNION, ALL, CASE, WHEN, THEN, ELSE, END, WITH, NOT, NULL, IN, IS, LIKE, BETWEEN, EXISTS, and RETURNING. count and desc are not in that set, so they stay as typed.

A new line starts before SELECT, FROM, WHERE, GROUP BY, ORDER BY, HAVING, LIMIT, OFFSET, the join forms, UNION, VALUES, SET, and RETURNING, when the current line already has text. GROUP BY and ORDER BY are glued into one token and consume the following BY. LEFT JOIN and the other direction-plus-JOIN pairs are glued the same way. AND and OR are uppercased but do not force a break, so they stay on the WHERE line. A comma ends the line immediately. An opening parenthesis ends the line and increases the indent by two spaces. A closing parenthesis ends the line, decreases the indent, and is written at the new indent.

Format, minify, and the sample button

The sample input select id, name from users where active = 1 order by name becomes SELECT id, then name on the next line with no indent, then FROM users, WHERE active = 1, and ORDER BY name. There is no aligned column under id. Minify of that result is SELECT id, name FROM users WHERE active = 1 ORDER BY name because minify joins tokens with spaces and then tidies comma and parenthesis spacing. Minify does not uppercase. If you minify the original lowercase sentence, select stays select. Line comments that start with -- are kept on their own line in format mode and deleted in minify mode.

Load sample inserts a query that selects u.id, u.name, and count(o.id) as orders, with a left join, a where, a group by, an order by, and a limit. Format will uppercase the known words, break before LEFT JOIN, WHERE, GROUP BY, ORDER BY, and LIMIT, and leave count and desc in their original case. AS becomes AS. The button only fills the field. You still press Format SQL.

Reading a generated INSERT

The CSV to SQL tool writes INSERT statements. This formatter does not know that tool's dialect settings. It only retokenizes whatever you paste. An INSERT with a column list and two value rows breaks before VALUES, indents inside each parenthesis, and puts a comma at the end of a row's closing parenthesis line. INSERT and INTO stay on the opening line because INTO is uppercased but is not a break keyword. A trailing semicolon is its own token, so it appears with a space before it: ) ;. Quoted identifiers such as "records" stay quoted and are not uppercased, because the quotes make one token. A doubled apostrophe inside a string, as in 'O''Neil', stays inside that token.

The guide Prepare CSV for PostgreSQL, MySQL or SQLite INSERT covers headers, NULL policy, and dialect quoting before any SQL exists. Formatting is the later reading step. This page will not connect to a server, create a table, or decide whether a value should be NULL. A statement that is missing a parenthesis is still printed. The formatter is not a parser with error positions.

Comments, empty input, and the file name

A -- comment is taken from the two dashes through the end of the line, without the line break. Format prints it on its own line at the current indent. Minify drops every token that starts with --, so the comment text is gone and the words on either side are joined. Block comments that use slash-star are not special. They are ordinary word characters and will sit inline.

An empty or all-whitespace field fails before tokenization. Format says Paste SQL to format. Minify says Paste SQL to minify. The panel is cleared. Download output uses the name sql-formatter.sql because the slug contains sql. The file is still the reformatted text, not a checked script. Copy output copies that same text. Neither control runs the statement.

Rules and limitations

Format uppercases the fixed keyword list, breaks before the clause set, breaks after commas, and indents two spaces per parenthesis level. Words outside the list, including count and desc, keep their case. Quoted strings and quoted identifiers stay intact.

Minify joins tokens, drops -- comments, and does not uppercase. Slash-star comments are not recognized. Empty input errors and clears the result. Download output names the file sql-formatter.sql. The statement is not executed.

Common problems

If name sits at the left margin under SELECT id, that is the comma rule, not a lost indent. The comma closes the line and the next word starts a new line at the current depth.

If minify left select in lowercase, that is expected. Uppercase is a format-mode behavior. Run Format SQL when you want the keyword list uppercased.

Frequently asked questions

About this tool

Maintained by Toolbench. For large or deeply nested files, split the input into smaller batches and verify representative results before using them in an import or application. Report reproducible problems through Contact.