How to convert JSONL to CSV
Load a JSONL, CSV, or TSV file, or paste its text. The page parses the input in your browser, creates the converted output there, and lets you download it. JSONL to CSV columns come from valid object records. Input stays in the browser; the page makes no request containing your file or pasted text.
Convert JSONL to CSV
- Use Drop JSONL, CSV, or TSV files here, select browse files, or enter text under Paste text and select Use pasted text. JSONL and NDJSON files open JSONL-to-CSV; CSV and TSV open the reverse. Pasted text and TXT use the first nonblank line to choose a direction.
- Read the warning area. Blank lines are skipped. Malformed JSON lines and valid values that are not objects are excluded because each CSV record comes from an object.
- Choose a Nested-value policy: JSON-stringify nested values, Flatten to dotted-path columns, or Selected-path columns. For selected paths, enter values in Dotted paths (comma-separated).
- Use the column list to keep, remove, or reorder fields. Choose a Delimiter, set Include header row, and enter the output File name.
- Review the CSV preview and select Download CSV.
Convert CSV to JSONL
- Load CSV or TSV, or paste tabular text.
- Set Delimiter to Comma (,), Tab, or Semicolon (;). Under Header row, choose First row is a header or No header row (use column_1, column_2, ...).
- Under Type inference, choose Infer numbers & booleans or Keep everything as strings. You can enter an exact Null marker (exact text) and select Treat empty field as null.
- Set Duplicate column rule to Auto-rename with suffix, Keep first occurrence's value, Keep last occurrence's value, or Error - block export. Review JSONL preview, then select Download JSONL.
What JSONL nested values become in CSV
JSON-stringify nested values keeps top-level fields as columns and writes objects or arrays as JSON text in cells. Flatten to dotted-path columns expands object paths. Selected-path columns reads the paths entered in Dotted paths (comma-separated). Missing paths and null values become empty cells.
Input JSONL
{"id":1,"user":{"name":"Ada"}}
Flatten output
id,user.name
1,AdaFields are discovered across valid records in first-seen order. The column list controls which fields remain and how they are ordered. Flattening warns when dotted column names collide. A later value overwrites an earlier value at that path.
JSONL and CSV warnings to check
For each category, details appear for up to 30 malformed or non-object JSONL lines. Additional items are counted. A whole-document JSON array can trigger a warning because JSONL expects one value per line; streamed files are checked for that shape only below 2 MB. Use the CSV JSON Converter for a whole JSON document.
The JSONL to CSV preview shows up to 200 records. The CSV to JSONL preview shows up to 50 output lines, and its schema summary examines up to 500 converted records. Files at least 4 MB are read in chunks when file streaming is available. Parsed rows stay in memory for preview and export. The CSV parser reports an unterminated quoted field.
Where JSONL to CSV conversion comes up
- Select fields from line-delimited records, set a delimiter, and download the CSV.
- When CSV headers repeat, choose Auto-rename with suffix before turning rows into JSONL.
- Paste a JSONL sample, check skipped lines, and inspect missing keys in the preview.
When another spreadsheet converter fits better
This page is part of Spreadsheet Convert Tools. Use the CSV to Excel Converter when the output should be an Excel workbook or split into sheets. Choose the Delimiter Converter to change between CSV, TSV, semicolon, pipe, or a custom delimiter. For XML output, use the CSV to XML Converter.
Frequently asked questions
Can this JSONL to CSV converter read a JSON array?
A whole-document array is treated as a non-object JSONL value and left out of the CSV records. The page shows an array warning. Use the CSV JSON Converter for a whole JSON document.
How does CSV to JSONL type inference work?
Infer numbers & booleans converts numeric text and true or false text to JSON numbers and booleans. Keep everything as strings leaves the parsed field values as strings.
What happens when JSONL lines are malformed?
Malformed nonblank lines are counted and left out of the CSV output. The warning lists details for the first 30, then gives the number of additional malformed lines.
Are JSONL and CSV files uploaded?
The code reads files and pasted text in the browser, creates the converted Blob there, and contains no request that sends the input content to a server.