Free JSON to SQL Converter — MySQL, PostgreSQL, SQLite INSERT Generator (2026)

Auto-Detected SQL Data Types Reference

Frequently Asked Questions

• What does this JSON to SQL converter do?

  This tool converts a JSON array of objects into SQL INSERT statements ready to run in MySQL, PostgreSQL, or SQLite. It auto-detects column data types from the JSON values, optionally generates a CREATE TABLE statement, and supports batch inserts for optimal performance. Paste your JSON API response, export data, or test fixtures and get runnable SQL in seconds.

• What JSON structure is required?

  The input must be a JSON array of plain objects — for example [{"id":1,"name":"Alice"},{"id":2,"name":"Bob"}]. Each object maps to one SQL row, and the object keys become column names. Arrays of primitives or nested arrays are not supported directly. If your JSON has a wrapper object, extract the array first (e.g., paste data.users, not the full response).

• How are SQL data types detected automatically?

  The tool inspects each value and infers the most appropriate SQL type: integers become INT or BIGINT (for values >2 billion), decimals become FLOAT, booleans become BOOLEAN (or 0/1 for SQLite), ISO date strings become DATE, ISO datetime strings become TIMESTAMP, long strings (>255 chars) become TEXT, nested objects/arrays become JSON, and everything else becomes VARCHAR(255).

• What is batch INSERT and why does it matter?

  A batch INSERT groups multiple rows into a single INSERT statement: INSERT INTO users (cols) VALUES (row1), (row2), (row3). This is significantly faster than individual INSERT statements because the database processes the transaction once instead of N times. For 1000 rows, batch size 100 produces 10 INSERT statements instead of 1000, which can be 10-100x faster.

• What is the difference between MySQL, PostgreSQL, and SQLite output?

  The main differences are identifier quoting and boolean handling. MySQL uses backtick quoting (\`column\`) and TRUE/FALSE for booleans. PostgreSQL uses double-quote quoting ("column") and TRUE/FALSE. SQLite uses double-quote quoting and stores booleans as integers (1/0). The INSERT syntax itself is identical across all three dialects.

• Can I use this to seed a test database?

  Yes, this is one of the most common use cases. Generate test fixture JSON (manually or from a factory library), convert to SQL, and run the INSERT statements to seed your test database. The optional CREATE TABLE output lets you set up the table schema alongside the data in a single .sql file.

• How are SQL injection risks handled?

  All string values are escaped by doubling single quotes (the SQL standard method: O'Brien becomes O''Brien). This prevents SQL injection in the generated INSERT statements. The column and table names are wrapped in dialect-appropriate quotes (backticks or double-quotes) to handle reserved words and special characters safely.

• What happens if objects in the array have different keys?

  All unique keys across all objects are collected as the column set. Objects missing a particular key have NULL inserted for that column. This handles heterogeneous arrays gracefully — you won't lose data from objects with extra fields, and missing fields default to NULL rather than causing errors.

• How do I handle nested JSON objects or arrays?

  Nested objects and arrays inside row objects are serialized to JSON strings and stored in a JSON column type. Most modern databases (MySQL 5.7+, PostgreSQL 9.4+, SQLite 3.38+) support JSON columns natively. If your database doesn't, flatten the nested data first or store it as TEXT.

• Can I convert large datasets?

  Yes. All processing runs in your browser — no server-side limit. For very large arrays (10,000+ rows), the conversion takes a moment but completes in the browser. Use a higher batch size (500) to keep the SQL file compact. Download the .sql file and import it using your database's bulk import tools (mysql -u user -p db < output.sql).

• Is my JSON data sent to any server?

  No. All SQL generation happens entirely in your browser using JavaScript. Your JSON data — which may contain sensitive user records, financial data, or proprietary business data — never leaves your device. The tool works offline after the initial page load.

• Is this JSON to SQL converter free?

  Completely free, no limits, no login. Convert any size JSON array to MySQL, PostgreSQL, or SQLite INSERT statements. Download as a .sql file or copy to clipboard. Includes optional CREATE TABLE and configurable batch size. All browser-based and private.