Turn NDJSON files into CSV
This makes a CSV out of the NDJSON you already have. CSV is a table saved as plain text, one row per line. Your file never leaves your computer.
Need the other direction? Convert CSV to NDJSON
How to convert NDJSON to CSV
- 1 Drop your NDJSON .ndjson or .jsonl file onto the page, or click to browse for it.
- 2 Check the options. Nothing is thrown away on the way to CSV, so there is no quality dial to set.
- 3 Convert. The work happens on your own machine, so how long it takes depends on your computer and the file.
- 4 Download the CSV, or add more files and do the whole set in one go.
Why convert NDJSON to CSV
- Opens in every spreadsheet, database and statistics package.
- Streams row by row, so files far larger than memory can be processed.
- Datasets published for download by governments and researchers.
- NDJSON: not valid JSON as a whole, so generic JSON tooling rejects it.
NDJSON compared with CSV
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | NDJSON | CSV |
|---|---|---|
| File extension | .ndjson | .csv |
| Colour depth | One JSON value per line, UTF-8, no wrapping array | Delimited text, RFC 4180 quoting, encoding not declared in-file |
| Introduced | 2013 | 1972 |
| Developed by | Community convention, also known as JSON Lines | IBM Fortran conventions, later RFC 4180 |
Quality and what changes
Both sides are lossless, so every pixel survives the trip intact and converting back returns the same image. What changes is the size and what the file can carry: CSV stores the data without compression, so expect a much larger file.
- One CSV limitation to keep in mind: only flat tables, so nested or repeated structures must be flattened.
Questions about NDJSON to CSV
Can I open a CSV in a browser?
No. No mainstream browser renders CSV natively, so it will download rather than display. That is fine when the file is heading into desktop software or an archive, and a problem if it is going on a web page.
Is my NDJSON file uploaded anywhere?
No. The whole thing runs inside the browser tab you already have open. Your NDJSON is read straight from your own disk, converted on your machine and handed back as a CSV. Nothing is sent anywhere, nothing is stored and there is no account.
Is there a file size limit?
There is no server-side limit because no server sees the file. The real ceiling is your device memory, since the input and the output both have to fit in the tab. A few hundred megabytes is usually fine on a desktop machine and considerably less on a phone.
Can I convert several NDJSON files at once?
Yes. Add as many as you like and they are processed one after another, then offered as separate CSV downloads or as a single ZIP. Speed depends on your own processor rather than on a queue.
Does the converter work offline?
Yes, after the page has loaded once. The engine is cached by the browser, so you can disconnect, reload and keep converting. That falls out of doing the work locally rather than being a separate mode you switch on.