How are numbers and booleans handled?

A cell that looks like a number or is exactly true/false becomes a real JSON number or boolean, not a quoted string — unless the cell was quoted in the source CSV (e.g. "00501") or has a leading zero before another digit, both of which usually signal a code rather than a number, and are kept as text.

What if two columns have the same header?

Object keys must be unique, so a duplicate header will overwrite the earlier one. Rename columns in the CSV first.

My file uses semicolons or tabs, not commas — will it still work?

Yes — pick the matching delimiter from the dropdown (comma, semicolon, tab or pipe) before converting.

What if my data has no header row?

Turn off "first row is a header." Every row is then treated as data, with auto-generated keys ("Column 1", "Column 2", ...) instead of the first row's values.

No — the conversion runs entirely in your browser.

CSV to JSON

Convert CSV data to a JSON array of objects, with a delimiter choice and a header-row toggle.

Processed locally in your browser. Your data is never uploaded.

Delimiter

First row is a header

Header row becomes the object keys; each data row becomes one object.
Choose comma, semicolon, tab or pipe as the delimiter — not comma-only.
Turn off "first row is a header" for headerless data — rows are still converted, with auto-generated "Column 1", "Column 2" keys.
Numbers and true/false values are typed correctly, not left as strings — a quoted cell or a leading-zero code (like a ZIP) is correctly kept as text.
Output is ready to paste into code, a request body or a fixture file.
Runs in your browser — safe for exports containing real data.

Why this is private

Processed locally in your browser. Your data is never uploaded.
Open your browser's DevTools → Network tab while using this tool — you won't see a request carrying your input, because it never leaves your device.
Nothing you enter is uploaded to a server or shared with us — the processing happens entirely on your device.

Overview

Converts CSV data into a JSON array of objects, using the first row as keys — numbers and booleans come out as real typed JSON values, not quoted strings. Also handles semicolon-, tab- and pipe-delimited files, and headerless data.

How to use it

1Paste CSV (or TSV/semicolon/pipe-delimited) data.
2Pick the matching delimiter if it isn't a comma.
3Turn off "first row is a header" if the data has none.
4Copy or download the JSON output.

Frequently asked questions

What people use it for

Turn a spreadsheet into API request bodiesConvert a list of records into a JSON array to POST to an endpoint.

Create test fixtures from real dataDrop a CSV sample into your test suite as JSON.

Load CSV data into a JS appGet an array of objects you can `import` or paste directly.

Move data between a spreadsheet and a NoSQL storeJSON is the common format for document databases.

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JSON to CSVConvert a JSON array of objects to CSV, with delimiter choice and nested-data flattening.CSV ViewerView a CSV file as a formatted table.CSV FormatterClean up CSV formatting and convert between delimiters.JSON Viewer & FormatterView, format, validate, edit and beautify JSON with an interactive tree view, plus a shareable link.

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CSV to JSON

CSV to JSON

Why this is private

Overview

How to use it

Frequently asked questions

How are numbers and booleans handled?

What if two columns have the same header?

My file uses semicolons or tabs, not commas — will it still work?

What if my data has no header row?

Is my data uploaded?

What people use it for

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