CSV to JSON converter
This makes a JSON out of the CSV you already have. JSON is the usual choice for HTTP API request and response bodies. The practical difference is that the result opens anywhere, which CSV files do not. Your file never leaves your computer.
Need the other direction? Convert JSON to CSV
How to convert CSV to JSON
- 1 Drop your CSV .csv file onto the page, or click to browse for it.
- 2 Check the options. Nothing is thrown away on the way to JSON, 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 JSON, or add more files and do the whole set in one go.
Why convert CSV to JSON
- A CSV will not open in a browser, so anything going onto a web page, into a document or into a message has to become a JSON first.
- Parsed natively by browsers and by every server language without a library.
- Human readable, so a malformed payload can be debugged by eye.
- Storing structured state in browsers and mobile apps.
- CSV: no type information, so identifiers and dates get mangled by spreadsheets.
CSV compared with JSON
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | CSV | JSON |
|---|---|---|
| File extension | .csv | .json |
| Colour depth | Delimited text, RFC 4180 quoting, encoding not declared in-file | UTF-8 text, six value types, no comments or trailing commas |
| Browser support | No browser support | Every browser |
| Introduced | 1972 | 2001 |
| Developed by | IBM Fortran conventions, later RFC 4180 | Douglas Crockford |
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: JSON stores the data without compression, so expect a much larger file.
- One JSON limitation to keep in mind: verbose compared to binary formats, with keys repeated on every record.
Questions about CSV to JSON
Is my CSV file uploaded anywhere?
No. The whole thing runs inside the browser tab you already have open. Your CSV is read straight from your own disk, converted on your machine and handed back as a JSON. 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 CSV files at once?
Yes. Add as many as you like and they are processed one after another, then offered as separate JSON 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.