CSV to JSON Converter

Use CSV to JSON Converter, review the result, and keep the original until the output is checked.

Input CSV
CSV Input
Output JSON
JSON Output
100% browser-side processing — your data is never uploaded to any server. · Per-tool input limit: 1 MB
100% browser-based No upload to server Free to use

Frequently Asked Questions About CSV to JSON Converter

Does it handle quoted fields containing the delimiter?

Yes. Fields wrapped in double quotes are parsed as one value, including embedded delimiters, doubled quotes and line breaks.

What is the first-row option for?

It decides whether the top row becomes JSON object keys or is treated as a normal data row. Turn it off when your file has no header.

Can it fix JSON with trailing commas or comments?

Yes. The repair step removes trailing commas, comments and a byte-order mark, turns single-quoted strings into double-quoted ones and quotes bare member names, then re-reads the document. Values it cannot infer, such as a Python True or a missing closing brace, still need a manual edit.

Why do large numbers change when I format JSON?

JavaScript numbers are IEEE-754 doubles, so most parsers rewrite an integer above 2^53 and lose its tail digits. This page keeps those long literals exactly as you typed them, but a parser elsewhere in your stack will not, so keep such ids as strings in the source document.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data-interchange format. It uses objects {}, arrays [], strings, numbers, booleans, and null.

Why format JSON?

API responses and config files are often minified. The CSV to JSON Converter expands them with indentation so you can spot nested keys, validate structure, and debug faster.