Are numbers converted to actual numbers?

No, deliberately. Everything stays a string, because inferring types is how leading zeros vanish from ZIP codes and long IDs turn into floats.

Does my data get uploaded?

No. It is parsed in your browser. For anything with customer records or internal figures in it, that is the entire reason to use this rather than a web service.

What about commas inside a field?

Handled, as long as the field is quoted per the usual CSV convention. Newlines inside quoted fields work too.

Convert CSV to JSON

Turn CSV into JSON in your browser. Nothing uploaded, no account, no row limit.

Open the converter

The first row of your CSV becomes the keys. Every row after it becomes an object, and the whole thing comes out as an array — the shape almost everything expects when it says it wants JSON.

Two details that trip people up. Empty cells become empty strings rather than null, because a CSV genuinely cannot tell the difference between the two and guessing would be worse than being predictable. And everything stays a string: a column of numbers comes out as \"1\", \"2\", \"3\", because deciding that a column of ZIP codes is really an integer is exactly how leading zeros get eaten.

Quoted fields, embedded commas and newlines inside quotes are handled properly. This matters more than it sounds — a lot of quick scripts split on commas and quietly mangle any row containing an address.

How it works

Drop the CSV on the page
Pick JSON as the output
Download the result

Worth knowing. Values stay strings and empty cells become empty strings — deliberately, so nothing is silently retyped. Very large files are limited by browser memory, since the whole file is parsed in the tab.

Questions

Are numbers converted to actual numbers?: No, deliberately. Everything stays a string, because inferring types is how leading zeros vanish from ZIP codes and long IDs turn into floats.
Does my data get uploaded?: No. It is parsed in your browser. For anything with customer records or internal figures in it, that is the entire reason to use this rather than a web service.
What about commas inside a field?: Handled, as long as the field is quoted per the usual CSV convention. Newlines inside quoted fields work too.

Everything the converter reads and writes →

Runs entirely in your browser. The file is never uploaded, so there is nothing for us to store, log or lose. No account, no watermark, no size paywall.