NDJSON to CSV Schema Inspector

Turn JSON Lines data into CSV without silently dropping late columns or nested object fields.

Choose an NDJSON or JSONL fileUp to 20 MB. Each non-empty line must contain one JSON object.

Protect spreadsheet formulasPrefix cells beginning with =, +, -, @, tab, or carriage return with an apostrophe.

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Data handling

Storage and export controls

Retention: The tool's working state is kept only while this page is open. Inputs and results are not saved to persistent storage by Got A Tool.
Export: The tool may prepare a result after you run it. It downloads or copies it only when you choose that action.

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How it works

Turn JSON Lines into a reviewable table

NDJSON files can introduce new fields late in a file or contain a few invalid lines. This workflow keeps those decisions visible instead of silently dropping data.

Step 01
Choose an NDJSON or JSONL file
Open one supported file from your device.
Step 02
Review fields and issues
The tool collects fields across readable object rows and identifies lines that cannot become CSV rows.
Step 03
Download the CSV
Export the readable rows after checking the column list and reported issues.

What this tool does and its limits

Nested object fields use dot notation. Arrays remain JSON text in one CSV cell so their structure is not guessed.
Invalid or non-object lines are reported rather than converted into incomplete rows.

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