JSON to JSONL Converter
Convert JSON arrays to JSONL (JSON Lines) format instantly. 100% client-side, your data never leaves your browser.
Input JSON
Drop a .json file here, or click to browse
Supports .json, .txt
Output JSONL
Paste or drop JSON content to convert
How to Convert JSON to JSONL
JSON to JSONL conversion takes a standard JSON array and transforms each element into a separate line. Each line in the output is a complete, valid JSON object, with lines separated by newline characters.
Our converter works entirely in your browser. No data is sent to any server. Simply paste your JSON text or drag and drop a file, and the JSONL output appears instantly.
If your input is a single JSON object (not an array), it will be output as a single JSONL line. Arrays are unpacked so each element becomes its own line.
What is JSON to JSONL Conversion?
JSON to JSONL conversion transforms a standard JSON array into newline-delimited JSON format. This is essential for preparing data for machine learning platforms like OpenAI, streaming data pipelines, and log processing systems that expect one JSON object per line.
For example, a JSON array with three objects becomes three lines in a JSONL file, where each line is a standalone JSON object without the wrapping brackets and commas.
Common Use Cases
ML Training Data
Prepare fine-tuning datasets for OpenAI, Hugging Face, and other ML platforms that require JSONL format.
Log Processing
Convert JSON data exports into JSONL for efficient streaming and processing with tools like grep and jq.
Data Pipelines
Transform JSON arrays into JSONL for ETL pipelines that process data line by line for better memory efficiency.
Batch API Requests
Convert JSON arrays into JSONL format required by batch APIs like OpenAI's Batch API.
Frequently Asked Questions
Is my data safe when converting?
Yes. All conversion happens locally in your browser. No data is sent to any server. Your JSON content never leaves your device.
What if my JSON is not an array?
If your input is a single JSON object, it will be output as a single JSONL line. Only arrays are expanded into multiple lines.
Does the converter preserve the data exactly?
Yes. Each element of the JSON array is serialized as a compact JSON string on its own line. No data is lost or modified during conversion.
Can I convert JSONL back to JSON?
Yes! Use our JSONL to JSON converter to transform JSONL files back into JSON arrays.