What are JSON Lines and NDJSON?
JSON Lines and newline-delimited JSON store one complete JSON value on each line. Each record is parsed independently instead of as one large document.
JSON Lines / NDJSON Validator
Paste JSON Lines or NDJSON to validate each line, find line-specific errors, and inspect parsed records.
NDJSON input
Paste one complete JSON value per line.
Validation result
Per-line status, summaries, and parsed JSON array output.
Ready to validate JSON Lines
Paste NDJSON on the left or load a sample. Each non-empty line is parsed as its own JSON value.
JSON Lines Validation Guide
Validate newline-delimited JSON records
JSON Lines and NDJSON files are common in logs, event streams, data exports, and batch API workflows because each line can be processed independently.
JSON Lines vs JSON arrays
A JSON array wraps records in brackets and separates them with commas. NDJSON keeps records on separate lines, which is easier for streaming logs and append-only exports.
Per-line validation
This validator does not parse the whole input as a single JSON document. It checks each non-empty line and reports the exact line, column, message, and preview.
Common NDJSON errors
Trailing commas, pretty-printed multi-line objects, comments, single quotes, missing closing braces, and accidental blank lines can break JSON Lines imports.
Logs and event streams
Use JSON Lines for application logs, analytics events, webhook batches, queue messages, and data warehouse imports where records are processed one at a time.
Private browser processing
Validation, summaries, reports, and formatted JSON array output run locally in your browser. NDJSON input is not uploaded or included in analytics.
JSON Lines Validator FAQ
Is NDJSON the same as JSON Lines?
They are commonly used to describe the same newline-delimited JSON pattern: one valid JSON value per line.
Can one JSON object span multiple lines?
No. In JSON Lines and NDJSON, each record must be complete on a single line. Pretty-printed multi-line objects should be converted before import.
Are blank lines allowed?
This tool ignores blank lines by default. You can change the option to report blank lines as warnings or errors when an importer is strict.
Does every line need to be an object?
Not always. JSON Lines can contain any valid JSON value, but many logging and data pipelines require one object per line. Enable that option when needed.
Can I convert valid NDJSON to a JSON array?
Yes. The parsed records preview shows valid records as a formatted JSON array that you can copy or download.
Does this validator upload my data?
No. Validation and report generation run locally in your browser.