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About Ndjson Validator Online
This tool validates NDJSON (Newline-Delimited JSON) — a format where each line is a self-contained JSON document. NDJSON is the standard for streaming logs, ingest pipelines, large data exports, and any system where records are processed one at a time.
The validator checks that every line parses as valid JSON, reports the line and column of any error, and gives a summary count of valid and invalid records. It also detects common issues like trailing commas, missing closing braces, and unescaped characters.
Useful for verifying log files before importing them to analytics platforms, validating data exports from databases, or troubleshooting integrations that produce streaming JSON.
How to use this tool
How to validate an NDJSON file (one JSON object per line)
Paste your NDJSON
Drop the text into the "NDJSON" field — one JSON value per line. The tool splits on `\n`/`\r\n`, trims blanks, and then runs `JSON.parse` on each remaining line.
Permissive on whitespace
Blank lines are skipped (not flagged). Trailing whitespace inside a line is tolerated — only the JSON parser's strictness applies.
Press Run
Result returns linesValidated (count of non-blank lines), ok (true if every line parsed), and errors[] — each entry is `Line N: <parser error>` so you can jump straight to the broken record.
Use for log/stream data
NDJSON is common in log shipping, event streams, and bulk-load endpoints (Elasticsearch, BigQuery). The validator catches a single bad line that would otherwise abort the whole ingestion.