Dev Tool

CSV to JSON Converter

Convert CSV data to JSON and JSON arrays back to CSV instantly. Runs entirely in your browser — no data is uploaded.

Delimiter: First row as headers Pretty print JSON Trim whitespace

Input0 rows

Output—

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Instant conversion

Paste CSV and get JSON in milliseconds. Handles thousands of rows without slowing down.

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Two-way conversion

Convert CSV to JSON or JSON arrays back to CSV — both directions supported.

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100% private

All processing happens in your browser. Your data never touches any server.

Frequently Asked Questions

Does the converter handle CSV files with headers?

Yes. If your CSV file has a header row, the converter uses those column names as the keys in the resulting JSON objects. Each subsequent row becomes a JSON object with the header names as keys and the row values as values.

What happens with commas inside CSV fields?

The converter correctly handles fields enclosed in double quotes, including quoted fields that contain commas, line breaks, or double quotes. This follows the RFC 4180 CSV standard for proper parsing.

Is there a file size limit for CSV conversion?

Conversion runs entirely in your browser, so there is no server-side file size limit. Performance depends on your device — files up to several megabytes convert instantly. Very large files may be slow depending on your hardware.

What CSV formats are supported?

Any standard CSV with comma, semicolon, tab or pipe delimiters. Quoted fields with embedded delimiters or newlines are handled correctly. The first row can optionally be treated as a header row.

What if my CSV has special characters?

Fields containing the delimiter, quotes, or newlines should be quoted in the CSV. Our parser handles standard RFC 4180 quoting correctly.

What is the maximum file size?

There is no server-side limit since everything runs in your browser. Performance depends on your device — most modern computers can handle CSVs with 100,000+ rows in seconds.

Turning a spreadsheet into JSON

Spreadsheets export CSV, while most APIs, apps and JavaScript code expect JSON. This converter reads the header row as field names and turns every row after it into an object. It supports custom delimiters and also converts in the other direction.

Choosing the delimiter

Comma is standard in English-language exports.
Semicolon is common in European versions of Excel, where the comma is the decimal separator.
Tab appears when you copy cells straight out of a spreadsheet.
Pipe (|) is used by some database and log exports.

If every row comes out as one long field, the delimiter setting is wrong.

Problems to watch for

The header row. Duplicate or blank column names produce clashing keys. Give every column a short, unique name.
Numbers stored as text. CSV has no data types, so decide whether values like 007 or phone numbers should stay strings.
Quoted fields. A value that contains the delimiter must be wrapped in double quotes, like "Smith, John".
Empty lines at the end of a file can produce empty objects at the end of the array.