Drop JSONL file here
Local processing only
Free online JSONL viewer — local processing only
Newline-delimited JSON (JSONL/NDJSON) is the standard format for logs, event streams, and large exported datasets. This local-first viewer reads your file entirely in the browser using DuckDB WebAssembly — your data never leaves your machine. Supports large files with paginated rendering, mixed schemas, and JSON export.
Frequently Asked Questions
- What is a JSONL file?
- JSON Lines (JSONL, also called newline-delimited JSON or NDJSON) stores one JSON object per line instead of a single array. It is commonly used for logs, streaming data, and large datasets exported from tools like Kafka, Elasticsearch, and data pipelines.
- How does this tool handle very large JSONL files?
- The file is loaded directly into an in-browser DuckDB engine (WebAssembly) and queried with pagination, so you can browse large files without loading everything into memory at once.
- Is my JSONL data uploaded anywhere?
- No. All processing happens locally in your browser. Your file is never sent to a server.
- What if my file has rows with different fields?
- The viewer merges columns across rows automatically, so lines with extra or missing fields are shown correctly with empty cells where data is absent.