sql-formatter-pro
A SQL formatter takes a flat or messy SQL query and rewrites it into a clean, indented, line-broken form that humans can actually read — keywords uppercased, JOINs aligned, subqueries indented, conditions broken across lines — making code review, debugging, and documentation dramatically faster. The ZTools SQL Formatter Pro runs entirely in the browser, supports MySQL / PostgreSQL / SQL Server / Oracle / BigQuery / Snowflake / SQLite dialects, configurable indent (2 / 4 / tabs), keyword case (UPPER / lower / preserve), and outputs ready-to-paste formatted SQL.
Use cases
Code review
Pull request includes a 500-character SQL query on one line. Format first; review second. Dramatically faster than parsing the raw blob.
Debugging slow queries
Production slow query in monitoring tool. Format to read its actual structure; identify the JOIN order or subquery that's the bottleneck.
Documentation
Including SQL examples in runbooks or docs. Formatted queries are readable; minified queries are not.
Cross-team handoff
Data analyst sends a query to engineer. Format ensures both read it the same way; reduces mistranslation.
How it works
- Paste SQL — Single query or multi-statement script. Tool tokenises preserving comments and strings.
- Pick dialect — Different dialects have slightly different keywords (MySQL's LIMIT vs SQL Server's TOP, BigQuery's STRUCT, Postgres's LATERAL). Right dialect = right formatting.
- Configure style — Indent: 2 spaces / 4 spaces / tabs. Keyword case: UPPER / lower / preserve. Comma placement: trailing or leading.
- Format — Tool re-emits SQL with proper indentation, line breaks at major clauses (SELECT / FROM / WHERE / JOIN / GROUP BY / ORDER BY), aligned subqueries.
- Copy / export — Output to clipboard or download. Original SQL untouched; format is purely cosmetic — the executed result is identical.
Examples
Input: SELECT a,b FROM t WHERE c=1 AND d>2 GROUP BY a ORDER BY b
Output: SELECT a, b\nFROM t\nWHERE c = 1\n AND d > 2\nGROUP BY a\nORDER BY b;
Input: Subquery: SELECT * FROM (SELECT id FROM users) sub
Output: SELECT *\nFROM (\n SELECT id\n FROM users\n) sub;
Input: CTE with WITH clause
Output: WITH cte AS (...) SELECT ... → properly indented across multiple lines.
Frequently asked questions
Will formatting change query behaviour?
No — formatting only adjusts whitespace and case. The parsed AST is identical; execution result is identical.
Why dialect-aware formatting?
BigQuery uses backticks for tables; Postgres uses double-quotes; MySQL uses backticks. Functions differ (DATE_TRUNC vs FORMAT_TIMESTAMP). Dialect-aware formatting respects each.
Should I use uppercase keywords?
Convention varies. Most style guides recommend UPPER for keywords (SELECT, WHERE) for visual contrast against identifiers. Some teams prefer lower for less visual noise. Pick one project-wide.
Is the SQL uploaded?
No — entirely client-side. Sensitive query logic stays private.
Can it format dynamic SQL with placeholders?
Yes — placeholders ($1, ?, :name) preserved. Tool sees them as values, not keywords.
What about embedded SQL in strings?
Format the SQL alone, then paste into your code. Formatter doesn't know about your host language's string escaping.
Tips
- Set up an automatic formatter in your editor (sqlfluff, prettier-plugin-sqlfluff). Manual formatting is unsustainable for large codebases.
- Pick a project-wide style and document it. Inconsistency is the real productivity drain.
- Format before commit — clean diffs make code review faster.
- For very long queries (multi-hundred lines), break into CTEs (WITH clauses); each CTE is an independent block easier to read than nested subqueries.
- Always test the formatted query — copy-paste, run, confirm same result. Trust but verify.
Try it now
The full sql-formatter-pro runs in your browser at https://ztools.zaions.com/sql-formatter-pro — no signup, no upload, no data leaves your device.
Last updated: 2026-05-05 · Author: Ahsan Mahmood · Edit this page on GitHub