Learn to efficiently manage large datasets by converting JSON to JSONL with our simple 5-step guide.

How to Create a JSONL File from Multiple JSON Objects

When working with large datasets or streaming data, it's often useful to store data in a JSONL format. JSONL stands for JSON Lines, which is a convenient format for storing structured data that may be processed one record at a time. It works by having each line in a file represent a separate JSON object. This tutorial will guide you through the process of creating a JSONL file from multiple JSON objects.


  • Basic knowledge of JSON data format
  • A text editor or a programming environment
  • Sample JSON objects to convert

Step 1: Understand JSON and JSONL Formats

JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy for humans to read and write and easy for machines to parse and generate. A JSON object is a collection of key-value pairs enclosed in curly braces.

JSONL (JSON Lines) is a format where each line is a valid JSON object, separated by newline characters. It's particularly useful for processing large files or streams of data.

Step 2: Prepare Your JSON Objects

Before converting your JSON objects to JSONL, ensure that each JSON object is valid. Each JSON object should be enclosed in curly braces and should not contain newline characters within strings.

Example JSON objects:

  "name": "Alice",
  "age": 30
  "name": "Bob",
  "age": 25

Step 3: Convert JSON to JSONL

To convert JSON objects to JSONL, you need to combine them into a single file with each JSON object on a separate line. Here's how to do it manually:

  1. Open a text editor and paste each JSON object on a new line.
  2. Ensure there are no trailing commas after the last key-value pair in each object.
  3. Save the file with a .jsonl extension.

Example JSONL file content:

{"name": "Alice", "age": 30}
{"name": "Bob", "age": 25}

Step 4: Automate the Process (Optional)

If you have a large number of JSON objects, it might be more efficient to automate the process using a scripting language like Python.

Here's a simple Python script to convert multiple JSON objects into a JSONL file:

import json

# Sample JSON objects
json_objects = [
    {"name": "Alice", "age": 30},
    {"name": "Bob", "age": 25}

# Convert and save to JSONL
with open('data.jsonl', 'w') as outfile:
    for json_obj in json_objects:
        json.dump(json_obj, outfile)

Run the script, and it will create a data.jsonl file with your JSON objects formatted as JSONL.

Step 5: Validate Your JSONL File

After creating your JSONL file, it's a good practice to validate it to ensure that each line is a properly formatted JSON object. You can use online validators or write a script to check each line.


You have now learned how to create a JSONL file from multiple JSON objects. This format is beneficial for handling large datasets and can significantly improve the efficiency of data processing tasks. Remember to validate your JSONL file to ensure data integrity.

By following these steps, you can effectively work with JSON and JSONL formats to manage your data in a more streamlined and efficient manner.

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