Free tool · CSV in · JSON out
CSV to JSON converter
Choose a delimited file and get JSON built from it. The header row becomes the property names, or you can keep every row as a plain array.
Paste the data instead
No file yet. Choose one to see the parsed rows and the JSON they produce.
Preview
How it works
- ReadThe delimiter is detected and the rows are parsed with quoting rules, exactly as in the other CSV tools.
- TypeA value becomes a JSON number only when it is unambiguously numeric; leading zeros and long identifiers stay strings.
- WriteThe JSON preview appears beside the grid, and the download button writes the whole file.
Questions
How are empty cells written?
As null, so a missing value stays distinguishable from the empty string.
What happens to duplicate header names?
The later column wins, because a JSON object cannot hold the same key twice. Rename one of the headers if both columns matter, or switch to the array-of-arrays shape.
Can I paste data instead of choosing a file?
Yes. Open “Paste the data” under the file box, paste the CSV text and press the button; the rest of the tool works the same way.
Is the conversion done on a server?
No. Parsing and JSON writing happen in your browser, and the file is never uploaded.
Keep going
Related tools, and the longer explanations behind them.