How to use JSONL
- 1. Paste JSONL or an array. One JSON value per line.
- 2. Join or split. Arrays become JSONL; JSONL becomes an array.
- 3. Sample. Take the first five rows.
- 4. Copy. Local only.
About this tool
JSONL is how logs, OpenAI fine-tunes, and BigQuery loads move many JSON values without wrapping them in a giant array. One bad line should not kill the rest — this parser tells you which line failed.
Line errors
If line 12 is invalid, you get that index back. Fix it without re-parsing a 50MB blob in your head.
Streaming
This tab still loads the whole file into memory. Stay under a few MB.
Code examples
JSONL
{"id":1}
{"id":2}