Convert JSONL to JSON, CSV, and back.
Four conversions, all in the browser: JSONL to a JSON array, a JSON array to JSONL, JSONL to CSV, and CSV to JSONL.
Runs in your browser. Whatever you drop or paste here is read by JavaScript in this tab and never sent anywhere. There is no upload endpoint on this site to send it to.
Common questions
How do I convert JSONL to JSON?
Wrap the lines in an array: each line becomes one element, separated by commas. That is what the JSONL to JSON mode does. The reverse — JSON to JSONL — takes a top-level array and writes each element on its own line.
What happens to nested objects in CSV mode?
A CSV cell holds one value, so anything that is not a string, number, boolean or null is written back as compact JSON inside the cell. It survives the round trip, but a spreadsheet will show it as text rather than as structure.
How are columns chosen for CSV?
Every key that appears anywhere in the file becomes a column, in the order the keys are first seen. Records missing a key get an empty cell rather than being dropped.
Does CSV to JSONL guess types?
Yes, conservatively. A cell holding exactly true, false, null, or a valid number becomes that value; everything else stays a string. Quoted fields, embedded commas and escaped quotes are parsed properly rather than split on commas.
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