NDJSON Viewer Online
View and inspect NDJSON files directly in your browser. Browse rows, check column names and data types — no upload required, your data stays on your device.
About the NDJSON viewer
NDJSON (newline-delimited JSON, also called JSON Lines) stores one JSON object per line. Application logs, event streams, BigQuery and Elasticsearch exports and OpenAI batch files commonly use it. The NDJSON viewer reads every line as a record and shows the result as a table, with the combined set of keys as columns and the total record count at the top.
This is faster than reading a log file line by line in an editor. It also shows problems that line-by-line reading hides: a field that is a number in most records but a string in a few, or a key that only appears in some records. Nested objects become STRUCT columns and are displayed as JSON text. The first 500 records are shown. Files with .ndjson or .jsonl extensions are both accepted. Every line must be complete JSON, so a file cut off mid-write will not load until the last line is removed.
What to check when you open a NDJSON file
- The row count equals the number of non-empty lines in the file.
- Timestamp fields are detected as TIMESTAMP rather than VARCHAR.
- Keys that only appear in some events show as columns that are mostly null.
- Numeric fields such as durations or status codes are not VARCHAR.
- Nested payload fields have the structure you expect, shown as JSON text in each cell.
Your file is processed locally in your browser and is never uploaded. The free limit is 50 MB per file; larger files work if your device has the memory for them.
Frequently Asked Questions
What happens if one line in my NDJSON file is invalid?
The file fails to load and an error message is shown. Common causes are a truncated final line from an interrupted write, or a pretty-printed object spread across several lines. Fix or remove that line and try again.
Is a .jsonl file the same as NDJSON?
Yes. JSON Lines and NDJSON are the same format. The viewer reads both extensions with the same reader.
Can I view only certain events, like errors?
The viewer shows the first 500 records with no filtering. Use the Filter tool, or the SQL Query tool with a WHERE clause such as level = 'error', to see matching records from the full file.
Related Tools
Convert NDJSON to CSV Online
Convert NDJSON files to CSV format directly in your browser. No upload required — your data never leaves your device.
Convert NDJSON to Excel Online
Convert NDJSON files to Excel format directly in your browser. No upload required — your data never leaves your device.
Convert NDJSON to Parquet Online
Convert NDJSON files to Parquet format directly in your browser. No upload required — your data never leaves your device.
Convert NDJSON to JSON Online
Convert NDJSON files to JSON format directly in your browser. No upload required — your data never leaves your device.
CSV Viewer Online
View and inspect CSV files directly in your browser. Browse rows, check column names and data types — no upload required, your data stays on your device.
Excel Viewer Online
View and inspect Excel files directly in your browser. Browse rows, check column names and data types — no upload required, your data stays on your device.
Parquet Viewer Online
View and inspect Parquet files directly in your browser. Browse rows, check column names and data types — no upload required, your data stays on your device.
JSON Viewer Online
View and inspect JSON files directly in your browser. Browse rows, check column names and data types — no upload required, your data stays on your device.