JSONL Viewer
Interactive JSONL (JSON Lines) viewer with expand/collapse and syntax highlighting. Converts JSONL to valid JSON array format.
JSONL
JSON Lines
Viewer
Development
Data
About JSONL Viewer
This interactive JSONL (JSON Lines) viewer normalizes newline-delimited JSON data into a valid JSON array format for easy visualization. Features include:
- Converts JSONL to valid JSON array format
- Displays all objects in a single tree view
- Expand and collapse objects and arrays at any level
- Multiple color themes for better readability
- Copy JSONL input or normalized JSON output
- Show/hide data types and object sizes
- Sort object keys alphabetically
- Syntax highlighting and formatting
- Error detection for invalid JSON lines (skips invalid lines)
- File upload support for .jsonl and .ndjson files
All processing happens in your browser - no data is sent to servers. Perfect for debugging streaming APIs, exploring JSONL datasets, and converting JSONL to JSON format.
Frequently Asked Questions (FAQ)
What is JSONL or JSON Lines format?
JSONL (JSON Lines) is a text format where each line is a valid JSON object. Also known as newline-delimited JSON (NDJSON), it is ideal for streaming data, log files, and big data processing.
How is JSONL different from regular JSON?
Regular JSON contains a single JSON structure (object or array), while JSONL has multiple JSON objects separated by newlines. This tool converts JSONL to a JSON array for easier visualization.
How does this tool normalize JSONL data?
The tool reads each line of JSONL input, parses it as a separate JSON object, and combines all valid objects into a single JSON array. Invalid lines are skipped with a warning message.
When should I use JSONL instead of JSON?
Use JSONL for streaming data, log files, large datasets, ETL processes, or when you need to process records independently. JSON is better for single structured data objects or API responses.
Can I upload JSONL files?
Yes, you can upload .jsonl, .ndjson, or .json files using the Upload File button. The tool will parse each line as a separate JSON object and display them all in the tree view.
What happens if a line contains invalid JSON?
Lines with invalid JSON will be skipped and a warning message will be shown indicating how many lines failed to parse. Only valid JSON objects will be displayed in the output.
Is my data sent to a server?
No, all processing happens in your browser. Your JSONL data never leaves your device, ensuring complete privacy and security.
Can I use this tool for NDJSON files?
Yes, NDJSON (Newline Delimited JSON) is the same format as JSONL. This viewer works perfectly with both .jsonl and .ndjson files.
Can I copy the normalized JSON output?
Yes, click the "Copy JSON Output" button to copy the normalized JSON array to your clipboard. This is useful for pasting into other tools or applications.