Free JSON to SQL Converter – Convert & Flatten API Responses Instantly

🔒 Client-Side & Private

JSON to SQL Converter

Flatten nested JSON and API responses into relational SQL tables.

How should we handle objects inside objects?

SQL Output

How to Convert JSON API Responses to SQL

Modern web development involves fetching data from APIs (like Stripe, Shopify, or Google), which almost always returns JSON. However, data analysts and backend engineers need that data in a Relational Database for reporting. Converting a hierarchical tree (JSON) into a flat table (SQL) is tedious.

Step-by-Step Guide

  1. Paste or Upload: Copy your JSON array (e.g., [{"id":1}, {"id":2}]) into the input box. You can also upload a .json file.
  2. Check Array Detection: If your JSON is wrapped in a root object like {"status": "ok", "data": [...]}, our tool automatically finds the array inside “data” and processes those rows.
  3. Choose a Strategy: JSON is deep; SQL is flat. Decide how to handle nested objects using the “Nested Data Strategy” dropdown (explained below).
  4. Generate: Click Convert. We scan every single row to ensure we capture all possible columns, even if they are missing in the first row.
💡 Understanding “Nested Data Strategy”
  • Stringify (Default): Takes a nested object like {"address": {"city": "NY"}} and converts it into a string '{"city": "NY"}'. This is best for modern databases like PostgreSQL (JSONB) or MySQL (JSON type).
  • Flatten Keys: Pulls values up to the top level. address.city becomes a column named address_city. Best for analytics warehouses (Snowflake/BigQuery).
  • Ignore: Simply discards any nested objects. Good if you only want the top-level IDs and names.

Technical Details

  • Auto-Type Inference: We scan your data to check if a column contains Integers, Booleans, or Strings, and generate the CREATE TABLE statement accordingly.
  • Escaping: Single quotes in your data (e.g., “O’Reilly”) are automatically escaped to 'O''Reilly' to prevent SQL errors.
  • Privacy: All processing happens in your browser’s memory. No data is sent to our servers.

Frequently Asked Questions

How does it handle Arrays inside JSON?

If a column contains an array (e.g., "tags": ["a", "b"]), it is automatically stringified into '["a", "b"]' so it fits into a single SQL cell.

Does this support JSONB for PostgreSQL?

Yes. If you select PostgreSQL and the “Stringify” strategy, the output is text-compatible. You can simply change the column type to JSONB in your database definition later.

My JSON file is 50MB. Will this crash?

Likely not. Since we run client-side, we can handle files as large as your browser’s memory allows. We have tested files up to 100MB successfully.

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