What is SQL Formatter?
SQL Formatter is a browser-based tool that takes a cramped, single-line, or inconsistently indented SQL query and reformats it into clean, readable, keyword-aligned SQL. It also works in reverse, compacting a multi-line query down to a single line when you need it inline. It understands the syntax quirks of several major dialects, so quoting and functions are handled correctly for the database you target.
SQL is the language of relational databases, and real-world queries can grow enormous — multi-table joins, nested subqueries, CTEs, window functions, and long CASE expressions quickly become unreadable when written or generated on one line. Formatting introduces consistent line breaks, indentation, and keyword casing so the logical structure of the query is visible at a glance.
The formatter supports Standard SQL, MySQL, PostgreSQL, SQLite, SQL Server, Oracle, BigQuery, and Snowflake, each of which has slightly different identifier quoting and syntax. Comments are preserved during formatting. Everything runs locally in your browser — your queries, which may reference production table and column names, are never uploaded.
Why use SQL Formatter?
Consistent formatting makes SQL dramatically easier to review, debug, and maintain. When keywords are aligned and clauses are on their own lines, you can spot a missing join condition, a misplaced WHERE, or an incorrect grouping instantly — problems that are nearly invisible in a wall of one-line SQL. This is especially valuable for machine-generated queries from ORMs and query builders.
Choosing the right dialect matters because identifier quoting differs: MySQL uses backticks, PostgreSQL and Standard SQL use double quotes, SQL Server uses square brackets. Formatting with the correct dialect keeps your quoted identifiers valid and avoids introducing errors, and compact mode is handy when you need to paste a query back into code or a single-line log.
Formatting locally keeps your schema private. Queries often reveal table names, column names, and business logic that you may not want to send to a third-party server. This tool processes everything in your browser and makes no network requests — you can verify that in the Network tab while you format.
Features
- Pretty-print SQL with aligned keywords, indentation, and line breaks
- Compact a multi-line query back down to a single line
- Supports Standard SQL, MySQL, PostgreSQL, SQLite, SQL Server, Oracle, BigQuery, and Snowflake
- Dialect-aware identifier quoting (backticks, double quotes, brackets)
- Preserves comments in the formatted output
- One-click copy of the result to your clipboard
- Download the formatted query as a .sql file
- Fully client-side — no query is ever uploaded, works offline
How to use SQL Formatter
- Paste your SQL query into the input panel on the left — a hand-written query, an ORM-generated statement, or a query copied from a log.
- Select the SQL dialect that matches your database from the dropdown so identifier quoting is handled correctly.
- The formatted query appears in the right panel automatically as you type.
- Use the Format / Compact toggle to switch between a readable multi-line layout and a single-line version.
- Copy the result to your clipboard or download it as a .sql file.
Example 1 — Format a one-line query
Paste a compact query and Format mode expands it with each clause on its own line and keywords uppercased.
Input
select id, name from users where active = true order by nameOutput
SELECT
id,
name
FROM
users
WHERE
active = true
ORDER BY
nameExample 2 — Compact a formatted query
Switch to Compact mode to collapse a formatted query back to a single line for embedding in code or a log entry.
Input
SELECT
a
FROM
bOutput
SELECT a FROM bCommon Mistakes
- Formatting with the wrong dialect: choosing PostgreSQL while your query uses MySQL backticks (or vice versa) can misinterpret quoted identifiers. Always pick the dialect that matches your actual database.
- Assuming formatting validates the query: this tool reformats syntax layout, it does not check that tables, columns, or joins are correct. A perfectly formatted query can still be logically wrong or reference nonexistent objects.
- Pasting multiple statements and expecting per-statement validation: formatting handles the text you give it, but errors in one statement of a batch can affect how the whole input is parsed.
- Losing dialect-specific syntax: some vendor-specific constructs are only understood by their own dialect. Formatting BigQuery or Snowflake SQL under the Standard dialect may not lay out proprietary syntax as expected.
- Expecting string contents to be reformatted: text inside string literals is left untouched. Only the SQL structure around literals is reformatted, which is correct — but do not expect data values to change.
- Relying on compact mode for minification savings: compact mode improves inlineability, not performance. The database parses formatted and compact SQL identically; whitespace has no effect on execution speed.
Developer Tips
- Format ORM- or query-builder-generated SQL before debugging it — machine-generated queries are almost always emitted on one line and become readable only after formatting.
- Standardize on uppercase keywords across your team by running queries through the formatter; consistent casing makes diffs and code review far cleaner.
- When a query behaves unexpectedly, format it first so the clause structure is visible — many logic bugs (a condition attached to the wrong clause) jump out immediately once the layout is clear.
- Use compact mode when you need to embed a query in a single-line log statement, a shell command, or a code string where multi-line SQL would be awkward.
- Keep the dialect selector set to your production database so quoting stays valid; a query formatted for the wrong dialect can silently become invalid when pasted back.
Frequently Asked Questions
- Does formatting change what my query does?
- No. Formatting only changes whitespace, line breaks, and keyword casing — the layout of the SQL. The database parser ignores that formatting entirely, so a formatted query and its compact version execute identically and return the same results. The one thing you must get right is the dialect, so that identifier quoting stays valid; the actual logic of the query is never altered.
- Why do I need to pick a SQL dialect?
- Different databases quote identifiers differently: MySQL uses backticks, PostgreSQL and Standard SQL use double quotes, and SQL Server uses square brackets. They also support different vendor-specific functions and syntax. Selecting the dialect tells the formatter how to correctly interpret and preserve those elements, so your query stays valid for the database you are actually targeting.
- Are my queries uploaded to a server?
- No. All formatting happens locally in your browser using JavaScript. Your SQL — which often exposes table names, column names, and business logic — is never sent to a server, logged, or stored. You can confirm this by opening the Network tab in your browser's developer tools while you format: there are zero outbound requests, and the tool continues to work even offline.
- Does the formatter validate my SQL?
- Only loosely. The formatter parses enough of the query to reformat it and will report an error if the input is not recognizable as SQL, but it does not verify that your tables exist, that column names are correct, or that joins are logically sound. Think of it as a layout tool, not a linter or a query planner — it makes SQL readable, it does not tell you whether the query is correct.
- Will comments in my SQL be preserved?
- Yes. Unlike the YAML formatter, the SQL formatter preserves comments in the output. Both single-line comments (starting with --) and block comments (/* ... */) are kept in place as the surrounding query is reformatted. This makes it safe to format documented or annotated queries without losing the explanatory notes your team relies on.
- Can I format very large queries or stored procedures?
- Yes, within reason. The formatter handles long queries with many joins, subqueries, and CTEs comfortably, and it processes everything in the browser so nothing is sent anywhere. Extremely large scripts or complex vendor-specific stored-procedure syntax may occasionally lay out differently than you expect, especially under the wrong dialect. For those cases, selecting the exact matching dialect gives the best results.
- What is the difference between Format and Compact mode?
- Format mode expands the query into a multi-line, keyword-aligned layout that is easy to read and review. Compact mode collapses it back to a single line, which is useful when embedding SQL in code, a shell command, or a one-line log entry. Both produce functionally identical SQL — the choice is purely about readability versus inlineability.