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JSONL

JSONL (JSON Lines) is equivalent to NDJSON: one JSON object per line, an alternative name for the same format.

Purpose

To provide the standard format for streaming JSON processing, synonymous with NDJSON.

Mechanism

Each line is a valid JSON value separated by \n. The only difference from NDJSON is that JSONL emphasizes one object per line (not arrays/scalars), but in practice the names are used interchangeably.

Use cases

  • Log files
  • Data pipeline streams
  • Paginated API responses
  • Database dumps

Examples

  • Input 
    {"id":1}
{"id":2}
    Output 
    Two JSON objects, one per line

    Same as NDJSON

Common errors

Confusing JSONL with a JSON array
JSONL has no outer []; each line is independent

Related terms

NDJSON
NDJSON (newline-delimited JSON) puts one independent JSON object per line, suiting streaming processing of large datasets.
GLOSSARY
JSON
JSON (JavaScript Object Notation) is a lightweight data interchange format based on JavaScript object literals, using key-value pairs and arrays.
GLOSSARY
CSV
CSV (comma-separated values) is a tabular data format that separates fields with commas; RFC 4180 defines the standard, and it is widely used for data import and export.
GLOSSARY

Related tools

Jsonl Format
Jsonl Format — pure client-side tool. Privacy-first, no server round-trip.
TOOL
Jsonl Validate
Jsonl Validate — pure client-side tool. Privacy-first, no server round-trip.
TOOL

References