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About Free Online SQL Formatter

Paste any SQL query, pick your dialect and keyword casing, and hit “Format” to get a clean, readable version with consistent indentation and layout. Ideal for MySQL, PostgreSQL, SQL Server, BigQuery, Snowflake and more – all formatted directly in your browser, client-side only.

Powerful Features of Our SQL Formatter

  • Live formatting: auto-beautifies SQL as you type or paste (toggleable live preview)
  • Customizable indentation: tabs or spaces with adjustable indent size
  • Dialect-aware formatting for PostgreSQL, MySQL, SQL Server, BigQuery, Snowflake and more
  • Smart keyword casing (UPPER, lower, or preserve original)
  • Optional blank lines between multiple queries for readability
  • Improved visual structure for CTEs, JOINs, CASE expressions and subqueries
  • File upload for `.sql` scripts with inline editing in the browser
  • One-click copy of formatted queries for your editor, IDE, or docs
  • 100% client-side execution via a modern SQL formatting engine – no servers, no logs

🛠️ How to Format SQL Like a Database Pro for sql-formatter

1

1. Insert Your SQL

Paste your query into the editor or upload a `.sql` file from your system. Syntax highlighting helps you quickly scan structure, aliases and joins.

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2. Configure Formatting

Pick your SQL dialect (PostgreSQL, MySQL, SQL Server, BigQuery, Snowflake, etc.), choose indentation (tabs or spaces), adjust indent size and set keyword casing (UPPER, lower, or preserve).

3

3. Transform Your Query

Click **Format** (or rely on Live Preview) to reflow your SQL into a clean, well-indented layout. Complex CTEs, CASE expressions and nested subqueries become much easier to read.

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4. Copy, Edit, or Save

Review the result, tweak directly in the formatted editor if needed, then copy your SQL back into your IDE, notebook, migration script or documentation.

Technical Specifications

SQL Dialect Support

The formatter understands a wide range of SQL dialects via a modern SQL parsing engine:

DialectSupport LevelKey Features
Standard SQL✅ FullCommon ANSI SQL constructs
PostgreSQL✅ FullCTEs, window functions, JSON operators, advanced joins
MySQL / MariaDB✅ FullBacktick identifiers, LIMIT/OFFSET, common MySQL syntax
SQL Server (T-SQL)✅ FullTOP, temp tables, T-SQL-style functions
SQLite✅ FullStandard queries, simplified dialect
Snowflake✅ FullWarehouse-style analytics syntax
BigQuery✅ FullNested fields, UNNEST, analytic query patterns
Redshift✅ FullWarehouse analytics, similar to PostgreSQL
Oracle / PL/SQL✅ PartialMany PL/SQL constructs, typical SELECT/DDL formatting
DB2, Hive, Spark, Trino/Presto, N1QL✅ PartialCore SELECT/DDL formatting for common patterns

Formatting Options (Mapped to Tool Logic)

The UI controls are wired directly to the underlying SQL formatting engine:

OptionChoices / RangeDefault
Indent StyleSpaces or TabsSpaces
Indent Size1–8 spaces (when using spaces)2
SQL DialectStandard, PostgreSQL, MySQL, SQLite, T-SQL, Snowflake, BigQuery, Redshift, Hive, Spark, DB2, PL/SQL, N1QL, Trino/PrestoStandard SQL
Keyword CaseUPPER, lower, Preserve originalUPPER
Blank Lines Between Queries0–5 lines0
Live PreviewOn / OffOn

Behavior & Limits

Formatting is deterministic and layout-focused:

AspectBehaviorNotes
ExecutionNever executes SQLOnly parses & rewrites text layout.
Max Input Size≈ 2 MB of SQL textFor huge generated queries, run a local CLI formatter.
Multiple StatementsRespects statement terminators (`;`)Optional blank lines between statements via settings.
IdempotencySame input → same formatted outputSafe to run repeatedly or in pre-commit hooks.

Command Line Alternatives

Want the same behavior in your local workflow or CI pipeline? Use a CLI formatter:

All Platforms

SQLFluff (Python, formatting + linting)

sqlfluff format --dialect postgres queries.sql

Formats and lints SQL with dialect-aware rules. Great for CI and style enforcement.

Prettier with SQL parser

npx prettier --parser sql --write queries.sql

Use a consistent Prettier-based SQL style across web and backend projects.

Run a formatter in pre-commit or CI so pull requests focus on logic, not indentation debates.

Real-World Applications

Query Optimization & Debugging

Make complex analytical queries easier to reason about.

  • Reformat 300+ line reporting queries with many JOINs and CTEs before debugging.
  • Standardize layout for team SQL style guidelines across microservices.
  • Visually inspect nested parentheses, CASE expressions and subqueries for logic errors.
WITH revenue AS (
  SELECT account_id, SUM(amount) AS total
  FROM payments
  WHERE created_at >= DATE '2024-01-01'
  GROUP BY account_id
)
SELECT a.id, a.name, r.total
FROM accounts a
LEFT JOIN revenue r ON r.account_id = a.id
ORDER BY r.total DESC NULLS LAST;

Documentation & Sharing

Present SQL cleanly in docs, wikis and code reviews.

  • Prepare nicely formatted SQL snippets for API and BI documentation.
  • Format migration scripts before committing them to version control.
  • Share readable query examples with stakeholders and data analysts.
-- Before: hard to read
select id,name,created_at from users where status='active' and created_at>now()-interval '30 days';

-- After: formatted
SELECT
  id,
  name,
  created_at
FROM users
WHERE status = 'active'
  AND created_at > NOW() - INTERVAL '30 days';

Analytics, BI & Data Science

Keep warehouse and BI queries consistent across notebooks and dashboards.

  • Format BigQuery / Snowflake SQL before saving in BI tools.
  • Normalize query style between notebooks and production pipelines.
  • Clean messy team queries before turning them into reusable views.

❓ Frequently Asked Questions

❓Does this tool execute my SQL queries?

No. The formatter never connects to a database or runs your queries. It only parses and rewrites the text layout (indentation, casing, line breaks) for valid SQL.

🔄Can I toggle keyword uppercase/lowercase?

Yes. Use the **Keyword case** option to choose between UPPER, lower, or preserving the original casing. This setting is applied consistently across all recognized SQL keywords.

⚡How fast is the live formatting?

For typical queries (even 1,000+ lines), formatting is nearly instant thanks to an optimized, client-side SQL formatting engine. Live Preview can be toggled on or off depending on your preference.

🔒Is my sensitive SQL data secure?

Yes. All formatting happens entirely in your browser – there are no server calls, uploads or logs. That said, you should still avoid pasting highly confidential data anywhere on the web if you can format it locally instead.

🧩What happens if my SQL has syntax errors?

If the input is too malformed for the parser, the formatter may return an error or leave parts unchanged. Fix obvious syntax issues (missing commas, unmatched parentheses, etc.) and try again.

Pro Tips

Best Practice

Format before debugging complex JOINs – aligned conditions make logic errors stand out.

Best Practice

Use UPPERCASE keywords and lowercase identifiers for a clean, consistent look across teams.

Best Practice

Combine the formatter with a linter like SQLFluff to catch anti-patterns and dialect-specific issues.

Best Practice

Use the same dialect setting in this tool and in your CLI/CI formatter to avoid subtle differences in layout.

Additional Resources

SQL Style Guide
Documentation
SQLFluff – Lint & format SQL
Documentation
sql-formatter Engine
Documentation

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