Convert NDJSON to TOML
Turn your NDJSON into a TOML. TOML is a settings file you can read at a glance, and it means exactly one thing whichever tool loads it. Your file never leaves your computer.
Need the other direction? Convert TOML to NDJSON
How to convert NDJSON to TOML
- 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 TOML, 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 TOML, or add more files and do the whole set in one go.
Why convert NDJSON to TOML
- Unambiguous rules, so two programs always agree on what it means.
- Dates and times are first-class values rather than strings.
- Python project metadata in pyproject.toml.
- NDJSON: records cannot be pretty-printed, since each one must fit on a single line.
NDJSON compared with TOML
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | NDJSON | TOML |
|---|---|---|
| File extension | .ndjson | .toml |
| Colour depth | One JSON value per line, UTF-8, no wrapping array | UTF-8 key-value text with tables, arrays and native date types |
| Developed by | Community convention, also known as JSON Lines | Tom Preston-Werner |
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: TOML stores the data without compression, so expect a much larger file.
- One TOML limitation to keep in mind: not built into browser or standard library tooling the way JSON is.
Questions about NDJSON to TOML
Can I open a TOML in a browser?
No. No mainstream browser renders TOML 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 TOML. 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 TOML 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.