Validate NDJSON Online — Report or Extract Valid Lines
Validate NDJSON: max lines, strict or skip bad lines, report counts or extract valid lines — entirely in your browser.
Developer notes
• onBadLine and outputMode are orthogonal. • strict + extractValidLines fails with empty extract if any line is bad. • skip + extractValidLines returns compact valid lines only. • Extract never pretty-prints. • Debounced ~300 ms while typing.
Options
When teams pick this route
• Verify an NDJSON export before upload. • Split valid lines out of a contaminated stream. • Cap work with maxLines before pasting huge dumps. • Get a count summary without extracting.
Worked examples
Mixed stream (skip + extract)
Input
Result
Strict report on bad line
Input
Result
Navigate related log tools
Format with format JSON logs, filter via filter JSON logs, or open the logs hub.
NDJSON validator FAQ
Strict, skip, extract
Is there a separate split-ndjson tool?
No. Use outputMode extractValidLines with onBadLine skip to salvage valid lines from a mixed stream.
What if I exceed maxLines?
Validation fails with an error citing count vs max. Lines are never silently truncated.
Does extract pretty-print?
No — extracted lines are always compact JSON.stringify output.
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