JSONL → JSON

Converts newline-delimited JSON (NDJSON) into a JSON array.

JSONL → JSON converts newline-delimited JSON (also called NDJSON or JSON Lines) into a single JSON array. Paste your JSONL where each line is one JSON value, and the tool parses every line and returns a pretty-printed array. It's handy when a log file, export, or streaming API gives you one JSON object per line but you need a normal JSON array to load into another tool or paste into code.

Common uses

• Turning a .jsonl log or event export into a JSON array you can open in an editor or viewer
• Converting NDJSON output from a streaming API or CLI into a single array for further processing
• Preparing JSON Lines data for tools or libraries that expect a JSON array instead of one object per line
• Quickly inspecting line-delimited records as a formatted, indented array
• Spotting a malformed record by line number before importing the data elsewhere

FAQ

Is my data sent to a server?

No. The conversion runs entirely in your browser using local JavaScript, and nothing you paste is uploaded or stored on any server.

What input format does it expect?

It expects newline-delimited JSON (NDJSON / JSON Lines), where each non-empty line is a single valid JSON value such as an object, array, number, string, or boolean. Lines are trimmed and blank lines are ignored.

What happens if a line is not valid JSON?

The tool stops and reports an error naming the specific line number, for example "Invalid JSON on line 3.", so you can find and fix the malformed record.

How is the output formatted?

Each line becomes one element of a JSON array, and the result is pretty-printed with 2-space indentation.

Does it support comments or trailing commas in the input?

No. Each line must be strict JSON parseable by the standard JSON parser, so comments, trailing commas, and unquoted keys are not allowed.

Related tools

• JSON Escape / Unescape
• JSON Flatten
• JSON Formatter
• JSON Merge
• JSON Minify
• JSON Patch (RFC 6902)
• JSONPath Evaluator
• JSON Repair