Is converting JSON to Microsoft SQL Server free?

Yes. Files up to 10MB convert free with no account. There is a limit of five conversions per day per IP address.

Will my JSON data keep its types in Microsoft SQL Server?

Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real Microsoft SQL Server types rather than everything becoming text. The mapping table above shows exactly what you get.

Do you store my file?

No. The file is written to a temporary directory, converted, and the directory is deleted as soon as your download has been sent.

Convert JSON to Microsoft SQL Server

Upload a .json or .ndjson file and get back a Microsoft SQL Server SQL script you can load straight into your database. Types are preserved rather than flattened to text. Free, no registration, up to 10MB.

1Upload your file

Click to upload or drag and drop

CSV, Excel, SQLite, SQL, DBF (max 10 MB)

2Choose target format

How your data is typed in Microsoft SQL Server

Generated from the converter's own Microsoft SQL Server type mapping — this is what it actually emits, not an example.

Your data	Microsoft SQL Server type
Whole number	BIGINT
Decimal (money)	DECIMAL(10,2)
Floating point	FLOAT
True / false	BIT
Date	DATE
Date and time	DATETIME2
Short text	NVARCHAR(255)
Long text	NVARCHAR(MAX)
Binary data	VARBINARY(MAX)

Working from a .json file

A .json file can be almost any shape, and only a few of those shapes are a table. What the reader accepts, and what it does with the rest, is the thing worth knowing before you upload one.

→A wrapper is unwrapped only when the object has exactly one key and that key holds a list of objects. {"meta": {...}, "data": [...]} has two keys, so it is read as a single row instead.
→An array of strings, or an array of arrays, is refused with "Expected a JSON array of objects" - there are no column names in it to build a table from.
→Columns are the union of the keys seen in the first 10,000 records, in the order they first appear. A key that shows up only after that is not part of the table.

Which SQL Server this runs on

Microsoft SQL Server is the full product name, and it covers a wide range of places to put a database: Express on a laptop, a Developer instance, a Linux container, a managed Azure SQL database. The script was written not to care which of them it lands in.

→There is no CREATE DATABASE, no USE, and no filegroup or collation clause anywhere in the file, so nothing in it can be refused by an edition that forbids those. Which database it populates is decided by your client's connection.
→No schema is named either, so the tables land in the default schema of whichever login runs the script - dbo for most logins. Moving them elsewhere afterwards is an ALTER SCHEMA ... TRANSFER.
→The primary key is emitted as an unnamed constraint, which the server materialises as a clustered index under a name it invents. Nothing else is indexed, so any index the source carried has to be rebuilt by hand.

Reading JSON

→JSON types are trusted: 1 and "1" stay different things.
→Numbers with a decimal point are read as exact decimals rather than floats.
→Both an array of objects and newline-delimited JSON work, and a wrapped array like {"data": [...]} is unwrapped automatically.
→Nested objects are kept as JSON rather than flattened into invented column names.

Writing Microsoft SQL Server

→String literals carry the N prefix, so non-ASCII text survives whatever collation the database uses.
→Timestamps become DATETIME2. T-SQL’s TIMESTAMP is a row-version counter, not a point in time.
→Identity columns are wrapped in SET IDENTITY_INSERT so explicit key values load.
→Statements are separated with GO in batches.

What you get

A ZIP containing dump.sql, plus a README with the exact command to load it. If anything about your data needed a judgement call, a _warnings.txt explains it.

Load this dump into SQL Server:

  sqlcmd -S HOST -U USER -P PASSWORD -d DATABASE -i dump.sql

Notes:

  - Text columns are NVARCHAR and literals carry the N prefix, so
    non-ASCII data survives regardless of database collation.
  - Timestamps are DATETIME2. T-SQL's TIMESTAMP type is a row
    version, not a point in time.

Questions

Is converting JSON to Microsoft SQL Server free?: Yes. Files up to 10MB convert free with no account. There is a limit of five conversions per day per IP address.
Will my JSON data keep its types in Microsoft SQL Server?: Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real Microsoft SQL Server types rather than everything becoming text. The mapping table above shows exactly what you get.
Do you store my file?: No. The file is written to a temporary directory, converted, and the directory is deleted as soon as your download has been sent.