Convert JSON to NDJSON Online
Convert JSON files to NDJSON format directly in your browser. No upload required — your data never leaves your device.
Drop your .json file here
or click to browse — max 50 MB
About this conversion
This tool converts JSON files to NDJSON format directly in your browser — no account required, no file upload, no waiting for a server. It processes your data entirely within your browser using WebAssembly, so nothing ever leaves your device.
The tool preserves all columns and data types from your source file and writes a valid NDJSON file ready to download. Large files are handled efficiently using a vectorised columnar engine.
Frequently Asked Questions
What is NDJSON format?
NDJSON (Newline-Delimited JSON) stores one JSON object per line, making it easy to stream, append, and process incrementally.
Is my JSON data private?
Yes — completely. Your file is never uploaded to any server. All conversion happens inside your browser using WebAssembly — locally, with no upload. Once you close the tab, nothing is retained.
What is the maximum file size?
The free limit is 50 MB. For larger files, performance depends on your device's available memory — most modern machines can handle 500 MB to 1 GB comfortably.
What is the difference between JSON and NDJSON?
Both JSON and NDJSON are common data formats used in engineering and analytics workflows.
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