Free CSV to JSON Converter

Convert CSV data to JSON arrays instantly. Handles quoted fields, commas in values, and multiline cells — all processed in your browser.

CSV Input

Drop a .csv file here or browse

How to Convert CSV to JSON in 3 Steps

Paste your data, convert, and download — all in your browser.

Paste or Upload CSV

Paste CSV data into the input area, or upload a .csv file from your device. The first row is used as column headers.

Convert to JSON

Click Convert. The parser handles quoted fields, escaped characters, and multiline values correctly.

Copy or Download

Copy the formatted JSON to your clipboard or download it as a .json file for use in your application.

Why Choose Our CSV to JSON Converter

RFC 4180 Parsing

The parser correctly handles quoted fields, escaped double quotes, commas inside values, and multiline cell content.

Clean JSON Output

Output is a properly formatted JSON array of objects with consistent indentation, ready for APIs, databases, or code.

100% Browser-Based

All processing happens locally in your browser. No data is uploaded to any server, keeping your information private.

Handles Ragged Data

Rows with fewer columns than the header get empty string values. Extra columns are safely ignored. No crashes on messy data.

File Upload Support

Drag and drop .csv files or use the file browser. No need to open large files in a text editor first.

Instant Download

Download the JSON output with one click. The file is generated entirely in your browser and ready for immediate use.

Frequently Asked Questions

What CSV format does the converter expect?

The converter expects standard CSV with the first row as column headers. Values are separated by commas, and fields containing commas, double quotes, or newlines should be enclosed in double quotes. This follows RFC 4180 and is compatible with files exported from Excel, Google Sheets, and most database tools.

How are quoted fields and escaped quotes handled?

The parser fully supports RFC 4180 quoting rules. Fields wrapped in double quotes can contain commas, newlines, and literal double quotes. Doubled double quotes inside a quoted field (e.g., ""hello"") are unescaped to a single double quote in the JSON output.

What does the JSON output look like?

The output is a JSON array of objects. Each row in the CSV becomes an object, with column headers as keys and cell values as string values. For example, a CSV with headers 'name,age' and one data row 'Alice,30' produces [{"name":"Alice","age":"30"}].

Does the converter detect numbers and booleans?

All values are output as strings to preserve the original data exactly as it appears in the CSV. This avoids issues like leading zeros being stripped from ZIP codes or phone numbers. If you need typed values, you can post-process the JSON in your application.

Is there a size limit for CSV files?

There is no server-side limit because all processing happens in your browser. Files up to about 50 MB convert smoothly on most modern devices. Larger files may work but could be slower depending on your device's memory and processing power.

Is my data private?

Yes. The entire conversion runs in your browser using JavaScript. Your CSV data is never sent to any server. This makes the tool safe for financial data, customer records, medical datasets, and any other sensitive information.

Can I upload a .csv file?

Yes. Click the upload area or drag and drop a .csv file. The converter reads the file in your browser and displays the contents in the input area so you can review before converting.

What happens if rows have different numbers of columns?

If a row has fewer values than there are headers, the missing fields are set to empty strings in the JSON output. Extra values beyond the header count are ignored. This handles ragged CSV files without errors.

When to Convert CSV to JSON

CSV remains the most common format for exporting data from spreadsheets, databases, and business tools. But modern web applications, APIs, and NoSQL databases work with JSON. Converting CSV to JSON lets you import spreadsheet data into JavaScript applications, send it to REST APIs, store it in document databases like MongoDB, or use it in configuration files.

The main challenge in CSV-to-JSON conversion is correctly parsing the CSV format. Real-world CSV files often contain commas inside quoted fields, escaped double quotes, multiline cell values, and inconsistent column counts. This tool implements a full RFC 4180 compliant parser that handles all of these edge cases, producing clean JSON output from even the messiest CSV files.