JSONL Validator
Validate pasted or local JSONL line by line, count valid, invalid, and blank lines, and optionally require object keys.
Runs entirely in your browser. Nothing you type is uploaded.
About this tool
Paste JSONL or choose a local .jsonl file to parse each nonblank line as one JSON value. Review totals plus line-numbered reasons and optionally require specific keys on every object; nothing is uploaded.
Questions & answers
- What is considered one JSONL record?
- Each nonblank physical line must contain exactly one complete JSON value. A JSON object cannot continue onto the next line.
- How are blank lines reported?
- Blank lines receive their own count and line-numbered detail. They are not added to the invalid JSON total.
- What does required-key checking do?
- Enter comma-separated keys to require them as own properties on every parsed object. Arrays, primitives, and objects missing a key fail that optional check.