How to Lint NDJSON and JSON Lines
NDJSON Lint
When to Lint JSON Lines
Validate streaming log files, NDJSON exports, and line-delimited API responses where each line must be independent JSON. Catch trailing commas, single-line arrays, and blank lines before ingestion pipelines fail.
Lint vs Schema Validation
This tool checks JSON syntax per line only. It does not validate schemas, required fields, or cross-line relationships. Use JSON Schema tools separately when you need structural validation.
Developer Tips
- Empty lines are reported as issues for strict JSONL parsers
- Large files should be split — browser memory limits apply
- Fix the first reported line before re-running on huge files
Frequently asked questions
What is NDJSON?
Newline-delimited JSON — one complete JSON value per line, common in logs and streaming APIs.
Does this validate JSON Schema?
No. It only checks that each non-empty line parses as JSON.