Convert JSON Lines to SQL Online

Paste a JSON Lines table below, edit it if you need to, and get SQL back. The conversion runs in your browser, so nothing is uploaded, there is no size limit and there is no signup.

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Nothing here is uploaded. The parsing happens on this page.

Edit

Paste or upload something above and it will appear here.

ToDataMarkupDocumentsCodeSchemasImages

Header rowDetect numbersTableStatementsRows per statement

The output will appear here once there is a table to convert.

What JSON Lines is

JSON Lines is one complete JSON object per line, with no enclosing array and no commas between records. The file is not valid JSON as a whole, and that is the point.

Log pipelines, machine learning datasets and anything that appends records or reads them in a stream.

What SQL is

SQL here means the statements that move a table into a database: INSERT INTO with a VALUES list, and optionally the CREATE TABLE that defines the columns.

Anyone seeding a database, moving a spreadsheet into an application, or writing a migration.

What changes when you convert JSON Lines to SQL

Each line is parsed on its own, so a corrupt record does not take the file with it. Keys are unioned across lines in first-seen order, so a record missing a field leaves that cell empty rather than shifting the columns.

String values are escaped by doubling any single quote. Statements are written in batches so a large table does not become one statement megabytes long, which many clients refuse. Ask for CREATE TABLE as well and column types are inferred: a column stays INT until a value does not fit, then widens to DECIMAL, then to VARCHAR.

What carries over from JSON Lines to SQL

One property of the JSON Lines has no home in SQL, and it is worth knowing which before you convert.

JSON Lines can hold a value that is itself a list or an object. SQL has only flat cells, so nested values are flattened into one cell rather than being spread across columns.

SQL marks header cells differently from data cells, so the keys are lifted out and written once as a marked header row rather than repeated on every row.

Both formats record types, so numbers, booleans and nulls survive as themselves rather than as text.

The identifier 007 comes out of the SQL as 007. Reading it as a number would have made it 7, and an id that changes value is worse than one that stays text.

The role "Analyst, data" survives with its comma, in one cell rather than split across two. That is the first thing to check in any converted table, and the usual place a SQL file goes wrong.

The quotes around Jonah "Jo" Pryce are left as a plain quote character in the SQL.

A worked example

Three rows of staff data, with an identifier that has a leading zero, a value containing a comma, a value containing quotes and one blank cell. Those are the four places formats disagree, so they are the four places to look.

JSON Lines in

{"id":"007","name":"Halima Yusuf","role":"Analyst, data","started":"2024-03-15","hours":"38.5"}
{"id":"012","name":"Jonah \"Jo\" Pryce","role":"Engineer","started":"2025-11-02","hours":""}
{"id":"104","name":"Wei Chen","role":"Manager","started":"2023-06-30","hours":"40"}

SQL out

INSERT INTO `staff` (`id`, `name`, `role`, `started`, `hours`) VALUES
  ('007', 'Halima Yusuf', 'Analyst, data', '2024-03-15', '38.5'),
  ('012', 'Jonah "Jo" Pryce', 'Engineer', '2025-11-02', NULL),
  ('104', 'Wei Chen', 'Manager', '2023-06-30', '40');

Questions

How do I convert JSON Lines to SQL?

Paste your JSON Lines into the box above or drop the file onto it. Check the table in the grid, then copy or download the SQL from the output panel. It takes one step and the data never leaves your browser.

What is the difference between JSON and JSON Lines?

JSON wraps records in an array, so a reader must load the whole document before it can use any of it, and appending means rewriting the file. JSON Lines has no wrapper, so records can be streamed and appended one at a time. Use JSON for a payload, JSON Lines for a log.

Are the generated INSERT statements safe to run?

Quotes in your data are escaped, so the statements are syntactically correct. They are not parameterised, which is fine for a one-off import you are running yourself and not fine as a pattern for application code that takes user input.

What happens to nested values?

SQL has no nested cell, so a list or object inside a JSON Lines value is flattened into a single cell rather than expanded into extra columns. Split it before converting if the parts need to be separate.

Is there a limit on file size?

No. The work happens on your own machine, so the limit is your machine's memory rather than an upload cap. A file with tens of thousands of rows converts in a second or two.

Is my data uploaded anywhere?

No. The parsing and generating are done by JavaScript running on this page. You can watch the network tab while you convert and see that nothing is sent.