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Runs in your browserConvert CSV to JSON
Most CSV-to-JSON converters online ask you to paste your data into a text box on their server. This one doesn't need to. Your header row becomes the object keys, each data row becomes an object, and you can optionally have numbers and booleans converted from strings to real JSON types.
How to use it
- Choose your CSV file.
- Decide whether to infer types — this turns "42" into 42 and "true" into true rather than leaving them as strings.
- Click Convert and download the .json file.
Questions
Is my file uploaded anywhere?
No. This page contains the whole tool — the JavaScript that does the work runs inside your browser tab, on your own machine. There is no server to upload to. You can confirm it yourself: open your browser's developer tools, switch to the Network tab, and run the tool. You will not see your file go anywhere. You can also disconnect from the internet after the page loads and it will still work.
What does type inference actually change?
With it on, a cell containing only digits becomes a JSON number, and "true"/"false" become booleans. Leave it off if you have values like postcodes, phone numbers or zero-padded IDs, where turning "01234" into 1234 would silently corrupt your data.
Can I get newline-delimited JSON instead of an array?
Yes — choose NDJSON as the output format. That gives one JSON object per line, which is what most data warehouses and bulk import APIs expect.