JSONL tools — convert between JSONL, JSON and CSV
Convert line-delimited JSON (JSONL / NDJSON) to a JSON array or CSV, and back again. It converts entirely in your browser (0 uploads, works offline).
How to use it
- Paste your JSONL (one JSON object per line) or a JSON array.
- Pick a direction: JSONL to JSON array, JSON array to JSONL, or JSONL to CSV.
- Copy or Download the result.
FAQ
How do I convert JSONL to CSV for free?
Paste your line-delimited JSON and choose JSONL to CSV. This page collects the union of keys across all records as the header and writes one row per line, on your device with no upload.
What is JSONL and how is it different from JSON?
JSONL (also called NDJSON) puts one complete JSON value on each line, with no wrapping array. It is ideal for streaming and log files because you can read it line by line. A JSON array holds the same records inside [ ... ].
Is my data uploaded anywhere?
No. The conversion runs entirely in your browser and nothing is transmitted or stored, which you can confirm by turning off your Wi-Fi.
What happens if one line is malformed?
The tool reports the exact line number that failed to parse so you can fix it, rather than silently dropping the record.
Limits
CSV output flattens only top-level keys; nested objects are written as JSON strings in the cell.
Related
The CSV-to-JSON converter handles plain CSV; the JSON formatter tidies a single document.
Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.