Want to convert CSV to JSON lines (JSONL / NDJSON / LDJSON)?
Try Withdata Data File Converter, a desktop CSV to JSON converter for Windows, MacOS, and Linux, Convert CSV to JSON lines, Easy and Fast.
- Can run in GUI mode, Step by Step, just a few mouse clicks.
- Can run in Command line, for Scheduled Tasks and Streams.
- Convert files locally and privately, avoid uploading large CSV file(s) to online services.
JSON Lines text format (JSONL), also called Newline-delimited JSON (NDJSON), or Line-delimited JSON (LDJSON). JSON Lines files may be saved with the file extension .jsonl, *.ndjson, *.ldjson.
Convert CSV to JSON lines (JSONL / NDJSON / LDJSON)
Choose CSV file -> Set target JSON Lines (JSONL / NDJSON / LDJSON) file -> Convert CSV to JSON lines (JSONL / NDJSON / LDJSON)
Click “Start a New Convert” at task dialog.
then show the wizard.
Select source/target file type.
1. Open a CSV file.
The CSV content:
2. Config target JSON Lines (JSONL / NDJSON / LDJSON) file.
3. Set rows options.
4. Convert CSV to JSON lines (JSONL / NDJSON / LDJSON).
See JSON lines file
Convert CSV to JSON lines (JSONL / NDJSON / LDJSON) in command line
Save “CSV to JSON Lines” session, then you can:
- Convert CSV to JSON lines (JSONL / NDJSON / LDJSON) in Windows command line.
- Convert CSV to JSON lines (JSONL / NDJSON / LDJSON) in Linux command line.
- Convert CSV to JSON lines (JSONL / NDJSON / LDJSON) in macOS command line.
Set scheduled tasks for converting CSV to JSON lines (JSONL / NDJSON / LDJSON)
You can schedule and automate this converting task by:
- Save session and create .bat (Windows) or .sh (Linux/macOS) file for “CSV to JSON lines” conversion.
- Set scheduled task for “CSV to JSON lines” conversion.
FAQ
More tools for JSONL / NDJSON / LDJSON.
Download Withdata DataFileConverter
CSV → JSON Lines reference
Type mapping
| Value kind | in CSV | in JSON Lines |
|---|---|---|
| Int | 1234 | 1234 (number) |
| Decimal | 1234.56 | 1234.56 (number) |
| Float | 1.234e+10 | 1.234e10 (number) |
| Text | quoted only when it contains a comma or a quote | "text" (string) |
| Long text | must be quoted; line breaks inside force multi-line records | "multi-line\ntext" |
| Date | 2026-09-18 | "2026-09-18" (string) |
| Datetime | 2026-09-18 14:30:00 | "2026-09-18T14:30:00Z" (string) |
| Binary | not representable - base64 or hex string | "base64:..." (string) |
| Boolean | TRUE / FALSE, or 1 / 0 depending on the writer | true / false (boolean) |
| JSON | the whole JSON value quoted, with internal quotes doubled | nested object on the same line |
Dialect differences
Both CSV and JSON Lines are file formats, so what differs below is how each one chooses to represent a value.
| Property | in CSV | in JSON Lines |
|---|---|---|
| identifiers | Double quotes; a literal quote is doubled ("" ) | Double quotes; backslash escapes (a newline inside a string... |
| dates | Conventional text: 2026-09-18 or 2026-09-18 14:30:00 | No date type: dates arrive as strings |
| binary | Not supported | Not supported natively - base64 inside a string |
| separator | Comma "," | Newline between records |
| encoding | No declaration - UTF-8 works only with a BOM | UTF-8 by definition |
| typing | None - every field is text | Same as JSON, but records cannot nest across lines |
| shape | Flat table, optional header row | Flat stream |
| ceiling | No formal limit; row count bounded by memory | Streams, so it scales past what a single JSON document can ... |
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