📊 CSV to JSON Converter

Free CSV to JSON converter

Turn spreadsheet data into JSON in one click. Paste CSV or TSV text, or upload a file exported from Excel or Google Sheets, and the converter produces clean JSON that you can copy or download. With a header row you get an array of objects, which is the format most websites and APIs expect. Without a header row you get an array of arrays. Your data stays in your browser and is never uploaded.

How to convert CSV to JSON

1. Paste your CSV text or click Upload file.
2. Leave the delimiter on Auto-detect, or choose comma, semicolon, tab or pipe.
3. Keep First row is header ticked if your first line contains column names.
4. Choose whether to detect numbers and booleans, and whether to trim spaces.
5. Click Convert to JSON, then copy the result or download it as a .json file.

What the options do

• Auto-detect delimiter: picks the most common separator in your first line. Many European spreadsheets use semicolons instead of commas.
• First row is header: uses the first line as the key names. Empty names become column_1, column_2 and so on, and duplicate names get a number added so no data is lost.
• Detect numbers and booleans: turns clean values such as 42, 3.14, true and false into real JSON numbers and booleans. Values with leading zeros, like zip codes or IDs such as 00123, stay as text so they are not damaged.
• Trim spaces: removes spaces from the start and end of every value.

Handles real-world CSV

• Values in double quotes that contain commas, such as a city and country in one cell
• Double quotes inside values, written as two quotes in a row
• Line breaks inside quoted cells
• Windows and Mac line endings, and a hidden byte order mark at the start of a file
• Blank lines, which are skipped

If a quoted value is never closed, the tool tells you which line it started on. If some rows have more or fewer cells than the header, you get a note with the number of uneven rows.

Common uses

• Loading spreadsheet data into a website, app or database
• Preparing test data for an API
• Moving data from Excel or Google Sheets into JavaScript or Python code
• Converting exported reports into a format that is easier to process

Limits and privacy

The converter accepts up to 5 million characters of pasted text, files up to 2 MB, and up to 200,000 rows. Everything is processed locally in your browser, so private business data does not leave your device.

Frequently asked questions

Why did my numbers stay as text?

Either Detect numbers and booleans is switched off, or the value is something like 007 or a very long number. Those are kept as text on purpose to avoid losing digits.

My file uses semicolons. Will it work?

Yes. Leave the delimiter on Auto-detect or choose semicolon.

How do I convert an Excel file?

In Excel, choose Save As and pick CSV. Then upload that file here. Only the current sheet is saved to CSV.

Can I convert the JSON back to CSV?

Yes, use the JSON to CSV converter on this site.