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JSON to SQL Table Generator

Generate CREATE TABLE scaffolding from JSON objects with nested structures and arrays.

Updated 20 Sep 2026

Nested object support Quick schema drafts Multiple dialects

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What this page sends

Your input: Processed in this tab and not sent to a server.
Share links: Share links put a Base64 copy of your input and output in the URL itself (after #d=). Anyone with the link can read it, so don't share a link that contains secrets.
Editor: On desktop screens the code editor (Monaco) is downloaded from cdn.jsdelivr.net; phones get a built-in lightweight editor instead.
Page load: Loading the page requests HTML, scripts and images from ByteKiln, fonts from Google Fonts, and sends Google Analytics page views, tool-usage events and catalog interactions (tool/category IDs, result status and whether a click followed search — never your input, output or search terms). Privacy & sharing

How the JSON to SQL Table Generator Works

The ByteKiln JSON to SQL generator reads a JSON object, infers appropriate SQL column types from the value shapes, and outputs a CREATE TABLE scaffold for your chosen database dialect. Everything runs in your browser.

How column types are inferred

String values become VARCHAR or TEXT. Whole numbers become INT. Decimal numbers become FLOAT. Booleans become BIT or BOOLEAN. ISO date strings are mapped to DATETIME or TIMESTAMP based on the selected dialect.

Nested objects

Nested JSON objects are extracted into separate CREATE TABLE statements. A foreign key column (e.g. parent_id) is suggested to link the child table back to its parent — review and adjust relationships as needed.

Using the output

The generated schema is a draft scaffold — a starting point, not a production-ready script. Add appropriate column widths, indexes, constraints, and foreign key enforcement before running against a real database.

Limitations

Types are inferred from the one sample you paste: a null value gives no type information, and every string becomes a VARCHAR/TEXT column unless it looks like an ISO date.
Lengths, precision and constraints are guesses — review VARCHAR sizes and numeric precision before using the script.
Nested objects become child tables with an <name>_id column, but no FOREIGN KEY constraint or index is written; arrays of objects are skipped and arrays of primitives are stored as TEXT.
It generates DDL only — no INSERT statements for the data itself.

FAQ

Short answers for the things developers usually ask before trusting a tool.

Which SQL dialects does the ByteKiln JSON to SQL tool support?

The tool generates CREATE TABLE statements for SQL Server (T-SQL), MySQL, and PostgreSQL. Dialect selection changes the data type mapping, quoting style, and constraint syntax used in the output.

How does the tool infer column types from JSON?

String values become VARCHAR or TEXT depending on the dialect. Numbers with decimals become FLOAT or DECIMAL. Integers become INT or BIGINT. Booleans become BIT or BOOLEAN. ISO date strings are mapped to DATETIME or TIMESTAMP.

What happens with nested JSON objects?

Nested objects are extracted into separate CREATE TABLE statements with a suggested foreign key column linking back to the parent table. You should review and adjust these relationships before using in production.

Is the generated schema ready for production?

It is a draft scaffold. Use it to quickly stub out your schema, then review column sizes, add indexes, and normalize the structure as needed for your workload.

Is my JSON sent to a server?

No. The JSON is processed in your browser and is not sent to a ByteKiln server. If you press Share, the link itself carries a readable copy of your input, so don't share links that contain secrets.

Related tools

Useful follow-ups when one conversion usually turns into three more.

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Read the JSON → SQL guide