Turn NDJSON files into YAML
Drop in an NDJSON and get a YAML back. YAML holds the same information as JSON but lays it out as an indented outline, so a person can read and edit it comfortably. Your file never leaves your computer.
Need the other direction? Convert YAML to NDJSON
How to convert NDJSON to YAML
- 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 YAML, 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 YAML, or add more files and do the whole set in one go.
Why convert NDJSON to YAML
- Comments and multi-line strings make it genuinely usable for configuration.
- Less punctuation noise than JSON for deeply nested structures.
- Application configuration that needs inline comments.
- NDJSON: nowhere to put information about the file as a whole.
NDJSON compared with YAML
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | NDJSON | YAML |
|---|---|---|
| File extension | .ndjson | .yaml |
| Colour depth | One JSON value per line, UTF-8, no wrapping array | Indentation-scoped UTF-8 text, a strict JSON superset since 1.2 |
| Introduced | 2013 | 2001 |
| Developed by | Community convention, also known as JSON Lines | Clark Evans, Ingy dot Net and Oren Ben-Kiki |
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: YAML stores the data without compression, so expect a much larger file.
- One YAML limitation to keep in mind: significant whitespace means a stray space can change the meaning silently.
Questions about NDJSON to YAML
Can I open a YAML in a browser?
No. No mainstream browser renders YAML 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 YAML. 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 YAML 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.