Quick Answer

Read JSONL one line at a time. Each line should be parsed as its own JSON value, which makes the format useful for logs, exports, and large datasets that should not be loaded into memory all at once.

For a no-code option, use the JSONL viewer. For code examples, parse each line, skip blank lines, and report line numbers when parsing fails.

The browser reader accepts JSONL, NDJSON, and plain-text files up to 50MB and shows the first 500 records for fast inspection.

Python Example

import json

with open("data.jsonl", "r", encoding="utf-8") as file:
    for line_number, line in enumerate(file, start=1):
        if not line.strip():
            continue

        record = json.loads(line)
        print(line_number, record)

JavaScript Example

const lines = input.split(/\r?\n/).filter(Boolean);
const records = lines.map((line) => JSON.parse(line));

Next Steps

• JSONL Parser Guide for more languages and performance patterns.
• JSONL Validator to debug invalid records.
• AI JSONL Readiness Checker to check Batch and fine-tuning records.
• JSONL Recipes for copyable Python, JavaScript, and jq examples.
• JSONL to CSV Converter to move record data into a spreadsheet.
• JSON Lines Format Specification for formal rules.