JSONL Validator
Validate a JSONL (JSON Lines) file line by line.
Processed locally in your browser. Nothing you paste is sent anywhere.
Overview
Validates a JSONL (JSON Lines) file — one JSON value per line — commonly used for fine-tuning datasets and log files. Reports exactly which lines fail to parse.
How to use it
- 1Paste JSONL content, one JSON object per line.
- 2Invalid lines are listed with their line number and error.