Paste or upload your SQL and format it into a clean, consistent .SQL file you can read, share, and reuse.
Messy, unformatted SQL is one of the most common sources of confusion in database development. Whether you inherited a legacy codebase full of single-line queries or you are debugging a complex stored procedure, readable SQL is essential. XConvert's free SQL Formatter transforms compressed, minified, or poorly indented SQL into clean, consistently styled code — entirely in your browser with no data sent to any server.
.sql file directly from your computer.SQL formatting is the process of restructuring SQL code so that it follows consistent indentation, line breaks, and keyword casing conventions without changing the logic or behavior of the query. Raw SQL generated by ORMs, query builders, or quick ad-hoc edits often ends up as a single long line or with inconsistent spacing. This makes it difficult to read, review, and debug. In collaborative environments, inconsistent formatting across team members creates noisy diffs in version control, making it harder to identify meaningful changes during code reviews.
A proper SQL formatter parses the query into its syntactic components — SELECT clauses, JOIN conditions, WHERE filters, subqueries, and expressions — then reconstructs the text with predictable whitespace and alignment. The result is code that is easier to scan visually, simpler to compare in diffs, and more maintainable over time. Unlike manual reformatting, an automated formatter applies rules uniformly across every query, eliminating style debates within teams. This is particularly valuable in organizations where multiple developers contribute SQL across different projects, tools, and skill levels.
SQL formatting is purely cosmetic. It does not alter table names, column references, aliases, or execution plans. The formatted output is semantically identical to the input, just far more readable. This distinction is important — you can safely format any query without worrying about changing its behavior, making it a zero-risk improvement to code quality.
| Feature | XConvert SQL Formatter | pgFormatter | SQL Formatter (npm) | Azure Data Studio |
|---|---|---|---|---|
| Price | Free | Free | Free | Free |
| Runs in Browser | ✅ | ❌ (CLI) | ❌ (Node.js) | ❌ (Desktop) |
| No Installation | ✅ | ❌ | ❌ | ❌ |
| MySQL Support | ✅ | ❌ | ✅ | ✅ |
| PostgreSQL Support | ✅ | ✅ | ✅ | ✅ |
| T-SQL Support | ✅ | ❌ | ✅ | ✅ |
| Oracle PL/SQL | ✅ | ❌ | Partial | ❌ |
| Custom Indent Width | ✅ | ✅ | ✅ | ✅ |
| Keyword Casing | ✅ | ✅ | ✅ | Limited |
| Privacy (No Upload) | ✅ | ✅ (local) | ✅ (local) | ✅ (local) |
Code review preparation — Before submitting a pull request or code review, format all SQL queries so reviewers can focus on logic rather than style. Consistent formatting makes diffs cleaner and review cycles faster. This is especially valuable in teams with mixed experience levels where formatting conventions may not be universally known.
Debugging complex queries — When a query returns unexpected results, formatting it with proper indentation reveals the structure of nested subqueries, JOIN conditions, and WHERE clauses that are invisible in a single-line format. Seeing the logical hierarchy of the query often makes the bug obvious immediately.
Migrating between database engines — When moving queries from MySQL to PostgreSQL or vice versa, formatting with the correct dialect highlights syntax differences and makes manual adjustments easier. Dialect-aware formatting ensures vendor-specific functions and quoting styles are preserved correctly. Pair this with XConvert's JSON to SQL converter for data migration tasks.
Documenting database logic — Technical documentation and wiki pages benefit from well-formatted SQL examples. Formatted queries are easier to annotate and explain to team members who may not be SQL experts.
Cleaning ORM-generated SQL — Object-relational mappers like Hibernate, SQLAlchemy, and ActiveRecord generate functional but often unreadable SQL. Paste the generated output into the formatter to understand what your ORM is actually doing.
Standardizing team coding style — Teams can agree on a formatting configuration (indent width, keyword case, comma placement) and use the formatter as the single source of truth, eliminating style arguments during code reviews.
XConvert's SQL Formatter uses a client-side parsing engine that tokenizes SQL input into a stream of keywords, identifiers, literals, operators, and punctuation. The tokenizer is dialect-aware, meaning it recognizes MySQL-specific syntax like backtick-quoted identifiers, PostgreSQL's :: cast operator, T-SQL's square bracket identifiers, and Oracle's CONNECT BY clauses. After tokenization, a lightweight recursive descent parser builds an abstract representation of the query structure, identifying clause boundaries, expression nesting depth, and parenthetical groupings.
The formatting engine then walks this structure and emits text according to the user's configuration. Indentation is applied based on nesting depth — subqueries, CASE expressions, and parenthesized lists each increase the indent level. Keywords can be transformed to uppercase, lowercase, or left as-is. Line breaks are inserted at clause boundaries (SELECT, FROM, WHERE, GROUP BY, ORDER BY, HAVING, LIMIT) and optionally before or after commas in column lists. The formatter handles edge cases like inline comments (-- and /* */), string literals containing SQL keywords, and quoted identifiers that should not be modified.
Because all processing happens in JavaScript within your browser, your SQL never leaves your machine. This is critical for developers working with queries that reference production table names, column names, or embedded credentials. There is no network request, no server-side logging, and no data retention. You can verify this by using the formatter with your network connection disabled.
Choose the correct dialect first — Selecting the wrong dialect can cause the formatter to misinterpret vendor-specific syntax. Always set the dialect before formatting.
Use uppercase keywords for readability — The SQL community convention of uppercase keywords (SELECT, FROM, WHERE) and lowercase identifiers makes queries scannable at a glance.
Prefer 4-space indentation for complex queries — While 2 spaces work for simple queries, deeply nested subqueries and CASE expressions are easier to follow with 4-space indentation.
Format before comparing — If you need to diff two versions of a query, format both with identical settings first using XConvert's Text Diff tool. This eliminates false positives from whitespace differences.
Validate after formatting — While the formatter preserves query semantics, always test formatted queries against your database to confirm behavior, especially with dialect-specific syntax.
Break up mega-queries — If you have a 500-line SQL script with multiple statements, consider formatting each statement individually for clarity. The formatter handles multi-statement input, but individual formatting gives you more control.
No. The formatter only modifies whitespace, line breaks, and keyword casing. It does not alter table names, column references, aliases, JOIN conditions, WHERE clauses, or any other semantic element. The formatted output is functionally identical to the input.
XConvert supports standard SQL, MySQL, PostgreSQL, SQL Server (T-SQL), Oracle PL/SQL, and SQLite. Each dialect has its own keyword set and syntax rules. Selecting the correct dialect ensures accurate formatting of vendor-specific features like MySQL's backtick identifiers or PostgreSQL's array operators.
No. All formatting happens entirely in your browser using client-side JavaScript. Your SQL never leaves your machine. There are no network requests, no server-side processing, and no data logging. You can use the tool offline after the page loads.
Yes. The formatter handles CREATE PROCEDURE, CREATE FUNCTION, BEGIN/END blocks, variable declarations, IF/ELSE statements, loops, and other procedural SQL constructs. Select the appropriate dialect (T-SQL for SQL Server procedures, PL/SQL for Oracle) for best results.
The formatter attempts best-effort formatting even when the input contains syntax errors. It will format the portions it can parse correctly and leave problematic sections as-is. For strict validation, consider using a dedicated SQL linter alongside the formatter.
Yes. Paste multiple statements separated by semicolons, and the formatter will process each one individually. Each statement receives proper indentation and line breaks independently.
Yes. Both single-line comments (--) and multi-line comments (/* */) are preserved in their original positions relative to the code. The formatter does not strip or relocate comments.
Since processing happens in your browser, the practical limit depends on your device's memory and processing power. Most modern devices handle queries up to several megabytes without issues. For extremely large SQL dumps, consider splitting them into smaller files first.
Yes. You can choose between trailing commas (the default, where commas appear at the end of each line) and leading commas (where commas appear at the beginning of the next line). Leading commas are popular in some teams because they make it easier to comment out individual columns.
XConvert's SQL Formatter offers comparable formatting quality to IDE plugins but with zero installation and cross-platform browser access. It is ideal for quick formatting tasks, sharing formatted SQL in documentation, or when you are working on a machine without your usual development environment. Unlike IDE formatters that are tied to a specific editor, XConvert works in any modern browser on any operating system. For database administrators who frequently work across different machines and environments, this accessibility is a significant advantage. For related data tasks, check out XConvert's CSV to SQL and JSON Formatter tools.