Export PostgreSQL table to JSON Lines (JSONL / NDJSON / LDJSON)

Want to export data from PostgreSQL table to JSON lines (JSONL / NDJSON / LDJSON)?

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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.

Export data from PostgreSQL table to JSON lines (JSONL / NDJSON / LDJSON)

Login to PostgreSQL -> Choose PostgreSQL table -> Set JSON lines file options -> Export PostgreSQL to JSON lines (JSONL / NDJSON / LDJSON)

Choose PostgreSQL and logon.

“Export From Table” for “PostgreSQL to JSON lines (JSONL / NDJSON / LDJSON)”.

Select JSON file type.

1. Choose PostgreSQL table.

2. Set JSON lines (JSONL / NDJSON / LDJSON) file options.

3. Set rows options.

4. Export PostgreSQL data to JSON lines (JSONL / NDJSON / LDJSON) table.

After exporting, you can view output JSON lines (JSONL / NDJSON / LDJSON) file.

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More tools for JSONL / NDJSON / LDJSON.

PostgreSQL → JSON Lines reference

Type mapping

Value kind	in PostgreSQL	in JSON Lines
Int	integer	1234 (number)
Bigint	bigint	9007199254740993
Decimal	numeric(p,s)	1234.56 (number)
Float	double precision	1.234e10 (number)
Text	varchar(n)	"text" (string)
Long text	text	"multi-line\ntext"
Date	date	"2026-09-18" (string)
Datetime	timestamp	"2026-09-18T14:30:00Z" (string)
Binary	bytea	"base64:..." (string)
Boolean	boolean	true / false (boolean)
JSON	jsonb	nested object on the same line

Dialect differences

PostgreSQL is a database server and JSON Lines is a file format, so the gap is wider than a dialect difference - the rows below are where values and structure stop lining up.

Property	in PostgreSQL	in JSON Lines
port	5432	—
identifiers	"double quotes"	Double quotes; backslash escapes (a newline inside a string...
row limit	LIMIT n	—
dates	timestamp, timestamptz, date, time	No date type: dates arrive as strings
long text	TEXT	—
binary	BYTEA	Not supported natively - base64 inside a string
separator	—	Newline between records
encoding	—	UTF-8 by definition
typing	—	Same as JSON, but records cannot nest across lines
shape	Tables of rows and columns	Flat stream
ceiling	—	Streams, so it scales past what a single JSON document can ...

Command line

Side	Command
PostgreSQL	pg_dump or COPY ... TO
PostgreSQL (load)	COPY ... FROM

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