Turn YAML files into NDJSON
Convert a YAML into an NDJSON right here on the page. NDJSON puts one complete record on each line, so a program can start working through a huge file immediately instead of waiting for all of it. Your file never leaves your computer.
Need the other direction? Convert NDJSON to YAML
How to convert YAML to NDJSON
- 1 Drop your YAML .yaml or .yml file onto the page, or click to browse for it.
- 2 Check the options. Nothing is thrown away on the way to NDJSON, 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 NDJSON, or add more files and do the whole set in one go.
Why convert YAML to NDJSON
- Constant memory processing regardless of how large the file grows.
- New records can be appended without rewriting the file.
- Machine learning training datasets read one example at a time.
- YAML: significant whitespace means a stray space can change the meaning silently.
YAML compared with NDJSON
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | YAML | NDJSON |
|---|---|---|
| File extension | .yaml | .ndjson |
| Colour depth | Indentation-scoped UTF-8 text, a strict JSON superset since 1.2 | One JSON value per line, UTF-8, no wrapping array |
| Introduced | 2001 | 2013 |
| Developed by | Clark Evans, Ingy dot Net and Oren Ben-Kiki | Community convention, also known as JSON Lines |
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: NDJSON stores the data without compression, so expect a much larger file.
- One NDJSON limitation to keep in mind: records cannot be pretty-printed, since each one must fit on a single line.
Questions about YAML to NDJSON
Can I open an NDJSON in a browser?
No. No mainstream browser renders NDJSON 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 YAML file uploaded anywhere?
No. The whole thing runs inside the browser tab you already have open. Your YAML is read straight from your own disk, converted on your machine and handed back as an NDJSON. 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 YAML files at once?
Yes. Add as many as you like and they are processed one after another, then offered as separate NDJSON 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.