JSON Lines / NDJSON Formatter

How to use JSON Lines / NDJSON Formatter

1. Paste your JSON Lines / NDJSON data, one object per line.
2. Each valid line is validated and pretty-printed; the first invalid line is flagged by number.
3. Copy the formatted output or download it as a file.

Why use our json lines / ndjson formatter?

JSON Lines (also called NDJSON or newline-delimited JSON) is the format used by log exporters, event pipelines, Elasticsearch bulk APIs and BigQuery export files. Working with it is harder than single-document JSON because one bad record can stop an entire import. This formatter splits your document into individual lines, parses each one, reports the exact line number of the first invalid entry, and pretty-prints every valid record with two-space indentation. The summary header shows how many lines were valid. All processing stays in your browser.

Repairing a BigQuery or log export with one bad record

JSON Lines files from logs, BigQuery exports and event pipelines fail completely when a single line is malformed. This formatter flags the offending line number so you can repair that one record.

{"event":"click","user":"alice","ts":1770000000000}
{"event":"view","user":"bob","ts":1770000000001}
{"event":"purchase","user":"alice","ts":1770000000002,}
{"event":"signup","user":"carol","ts":1770000000003}

2 of 4 lines are valid JSON before the error on line 3.

Invalid JSON on line 3: Unexpected token }, ... (at character 58)

Line content:
{"event":"purchase","user":"alice","ts":1770000000002,}

Remove the trailing comma on line 3 and re-run to see all four records pretty-printed.

Paste a JSONL/NDJSON export from a log pipeline, BigQuery, or Elasticsearch bulk file — find and fix the single broken record instead of hunting through thousands of lines.