Free JSON / CSV / JSONL Converter

How this tool computes its result

Converts between three formats using a common intermediate representation. JSON <-> CSV: parses CSV with quote and escape handling (quoted cells, ""-> " escape), treats first row as headers, maps remaining rows to objects keyed by headers. Converts JSON to CSV by flattening arrays of objects into rows and auto-detecting headers. JSON <-> JSONL: JSONL is one JSON object per line; conversion is trivial line-by-line parsing/stringification. Detects source format via select dropdown; target format chosen separately. Errors are caught and surfaced.

Worked example

Converting JSON [{"name":"Alice","age":30},{"name":"Bob","age":25}] to CSV produces "name,age" header, then "Alice,30" and "Bob,25" rows. Converting the same JSON to JSONL produces two lines: {"name":"Alice","age":30} and {"name":"Bob","age":25}. CSV to JSON reconstruction parses headers, maps rows back to objects.

When not to use this tool

This assumes flat object structures - it does not handle nested JSON objects (it would stringify them as JSON strings in CSV cells), arrays within fields (treated as JSON strings), or column reordering; for complex data, use a spreadsheet editor or specialized ETL tool.

Common mistakes

• - Pasting CSV with quoted cells containing commas (e.g., "name, city" as one cell) and expecting proper parsing - the tool does handle quoted commas correctly, but manually copy-pasting from a spreadsheet may lose quote escaping depending on your clipboard software.
• - Assuming JSONL means one JSON array; it actually means one JSON object per line - pasting [{"a":1}, {"b":2}] into JSONL mode will fail to parse because the array syntax is not valid JSONL.
• - Converting to CSV and pasting the output back into Excel or Google Sheets, then expecting all data to round-trip losslessly - character encoding and quote handling can diverge; test with a small sample first.

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