Dev Tools

SQL Tools

Free SQL tools online: SQL formatter and beautifier, SQL minifier, SQL validator, JSON to SQL INSERT, string escape, query diff, JOIN visualizer, LIKE tester, and a SQL cheat sheet. Pretty-print PostgreSQL, MySQL, SQLite, SQL Server, BigQuery, and Snowflake in your browser. Nothing is uploaded.

10 tools · 100% browser-based · No uploads · No signup

About these SQL tools

Free SQL tools online to format, check, and convert queries in your browser. The SQL formatter (SQL beautifier / pretty print SQL) indents PostgreSQL, MySQL, SQLite, SQL Server, BigQuery, and Snowflake. Minify SQL, validate syntax, convert JSON to SQL INSERT, escape strings, diff two queries, visualize JOINs, test LIKE patterns, explain a statement in English, or open the SQL cheat sheet.

Nothing is uploaded and nothing is executed. There is no database behind these pages. That is the point when the query contains customer emails, production table names, or credentials in a comment.

Tools in this category

SQL Formatter

SQL is not one language. Pretty-print without a dialect will “fix” Postgres into MySQL, then you paste it into prod.

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SQL Minifier

SQL minifier online. Compress SQL by stripping comments and extra whitespace while keeping string literals intact. Free SQL compressor in your browser.

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SQL Validator

SQL validator online. Check SQL syntax, find unclosed quotes and parentheses, and see parse errors with line numbers. Free SQL checker, no upload.

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JSON to SQL Converter

Convert JSON to SQL online. Turn a JSON array of objects into INSERT statements, optionally with CREATE TABLE. Free JSON to SQL converter in your browser.

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SQL Escape

SQL escape and identifier quoting online. Quote string literals and column names for PostgreSQL, MySQL, SQLite, or SQL Server. Unescape pasted SQL too.

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SQL Diff

Compare two SQL queries online. Format both, then diff. Whitespace and keyword case do not count as changes. Free SQL compare tool.

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SQL JOIN Visualizer

SQL JOIN visualizer online. See INNER, LEFT, RIGHT, FULL, CROSS, SEMI, and ANTI joins with sample tables and result rows. Free SQL join explainer.

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SQL LIKE Tester

SQL LIKE tester online. Test % and _ wildcards, ESCAPE, and case-insensitive ILIKE against sample strings. Free LIKE pattern matcher.

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SQL Explainer

SQL query explainer online. Break a SELECT, INSERT, UPDATE, or DELETE into clauses in plain English. Free SQL explainer in your browser.

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SQL Cheat Sheet

SQL cheat sheet online. Joins, data types, window functions, dates, and NULL handling for PostgreSQL, MySQL, and SQLite. Free searchable SQL reference.

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How these tools run in your browser

The formatter and validator use a dialect-aware SQL parser in this tab. The minifier, LIKE tester, explainer, and JSON converter tokenize strings and comments so literals are not rewritten. JOIN results are computed from a small fixed sample (users and orders), not from your data. Queries never leave the browser.

Common Use Cases

  • Pretty-print a one-line query from an ORM or slow-query log
  • Turn a JSON API sample into INSERT statements for a local seed
  • See INNER vs LEFT vs FULL JOIN with a concrete result table
  • Test a LIKE or ILIKE pattern before you ship it
  • Explain a JOIN-heavy SELECT to a teammate without running it

Common Mistakes

A syntax check is not EXPLAIN. Valid SQL can still fail at runtime.
Pick the dialect that matches your engine. Postgres dollar quotes are not MySQL.
JSON to SQL infers types from the sample. It will not add indexes or SERIAL.
Mega-scripts can freeze the tab. Split them or use a local CLI.

Frequently Asked Questions

How do I format SQL online?

Open the SQL Formatter, paste the query, pick PostgreSQL, MySQL, SQLite, SQL Server, BigQuery, or Snowflake, and copy the pretty-printed SQL. Nothing is uploaded.

How do I convert JSON to SQL INSERT?

Open JSON to SQL Converter, paste an array of objects, set the table name and dialect, and copy the INSERT statements. Enable CREATE TABLE if you need a matching schema guess.

Do you run my SQL against a database?

No. There is no Postgres, MySQL, or SQLite here. The tools only format, parse, and transform text in this tab.

Is it safe to paste production queries?

The text never leaves this browser tab. A compromised extension could still read the page. For highly sensitive SQL, prefer a local editor.