a {"id": 1, "event": "signup", "user": "ada", "at": "2026-11-02T09:14:00Z"}
{"id": 2, "event": "login", "user": "ada", "at": "2026-11-02T09:15:12Z"}
{"id": 3, "event": "purchase", "user": "ada", "at": "2026-11-02T09:21:40Z", "total": 89.99}
JSON Lines to JSON
Paste JSON Lines and press To JSON array in the Convert panel.
Skip to editor
a polyxmedia product
JSONUTF-8
Spaces: 2
How do I convert JSONL to JSON?
To convert JSON Lines to JSON, paste the lines above, open Convert and press To JSON array. Every line becomes one item in a formatted array, and blank lines are skipped. To JSON Lines does the reverse, writing each item of an array on its own line.
If a line isn't valid JSON, you get its line number and the parser's message, so you can find the bad record in a file with thousands of them. JSONL is what BigQuery exports, logging tools and OpenAI batch files use.
- Paste your JSON Lines into the editor.
- Open Convert and press To JSON array.
- Copy or save the array.
Example
{"id": 1, "event": "signup", "user": "ada", "at": "2026-11-02T09:14:00Z"}
{"id": 2, "event": "login", "user": "ada", "at": "2026-11-02T09:15:12Z"}
{"id": 3, "event": "purchase", "user": "ada", "at": "2026-11-02T09:21:40Z", "total": 89.99}[
{
"id": 1,
"event": "signup",
"user": "ada",
"at": "2026-11-02T09:14:00Z"
},
{
"id": 2,
"event": "login",
"user": "ada",
"at": "2026-11-02T09:15:12Z"
},
{
"id": 3,
"event": "purchase",
"user": "ada",
"at": "2026-11-02T09:21:40Z",
"total": 89.99
}
]Questions people ask
What is the difference between JSONL and NDJSON?
Nothing that matters in practice. Both mean one complete JSON value per line, separated by newlines, and the names are used interchangeably.
Why does JSON.parse fail on my JSONL file?
JSON.parse reads exactly one value, so it stops at the start of the second line with Unexpected non-whitespace character after JSON. Parse each line separately or convert the file to an array here.
Is my data uploaded anywhere?
No, this runs entirely in your browser, so nothing you paste is sent to a server. The only feature that sends data anywhere is the optional AI assistant, and only when you actually ask it something.