Convert JSON to JSONL free, in seconds. Paste your data below, press Convert, then copy the result and stream it into logs, pipelines and data tools. Everything runs in your browser, so nothing is ever uploaded.
JSON input
Paste your JSON below, then press Convert.
Tip: arrays of objects convert best. A single object becomes one row.
JSONL output
Waiting for JSON input.
JSON parse error
Private by design: conversion runs entirely in your browser with built-in code, so your data never leaves your device.
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How this conversion works
Paste JSON into the input box and press Convert (or just keep typing, conversion happens as you type). The tool parses it with the browser's native JSON parser, then writes one compact JSON object per line, the standard JSON Lines format. Conversion runs entirely in your browser with built-in code, so your data never leaves your device.
Using JSON Lines
JSON Lines puts one complete JSON object on each line with no outer array and no trailing commas. Unlike a JSON array, which must be parsed whole, JSONL can be read line by line, which makes it ideal for huge files, log pipelines, BigQuery imports, Elasticsearch bulk loads and machine-learning datasets. Each line keeps the full nested structure of its record.
JSON Lines is the standard for streaming data: log pipelines, BigQuery imports, Elasticsearch bulk loads and ML training sets all accept one JSON object per line. It is the format of choice when a JSON array would be too big to parse at once.
How is my JSON parsed?
With the browser's native JSON parser, so even large documents convert fast. An array of objects becomes one row per object, a single object becomes a single row, and nested values are flattened with dot notation (for example contact.city).
How is JSONL different from a JSON array?
A JSON array must be loaded and parsed whole, while JSONL can be processed line by line. That makes JSONL far better for huge files and streaming processors that handle records as they arrive.
Is nested data preserved?
Yes. Each line keeps the full nested structure of its record as compact JSON, so nothing is flattened or lost in the conversion.
Is my data sent to a server?
No. conversion runs entirely in your browser with built-in code, so your data never leaves your device.