Input CSV
JSON Output
CSV to JSON Converter
Transform CSV data into JSON format with automatic delimiter detection
What This Tool Does
This converter takes CSV (comma-separated values) data and transforms it into JSON format. It handles standard CSV conventions including quoted fields with commas, detects delimiters automatically, and generates clean JSON output suitable for APIs and web applications.
The conversion runs in your browser. When you paste CSV text or upload a file, it processes the data locally without sending anything to a server.
Who Needs This
Web developers building applications that consume JSON APIs often receive data exports in CSV format. This tool converts that data into JSON so you can integrate it with JavaScript applications or store it in document databases like MongoDB.
Data analysts who export reports from Excel or database tools can convert CSV exports to JSON for visualization libraries like D3.js or Chart.js that expect JSON-formatted data.
Backend developers testing API payloads can quickly convert CSV test data into JSON format for seeding databases or mocking API responses.
Key Features
Automatic Delimiter Detection
Detects whether your CSV uses commas, semicolons, tabs, or pipes as separators without requiring manual configuration.
Header Row Handling
Converts the first row into object keys when headers are present, or generates numeric indices for arrays when headers are absent.
Quoted Field Support
Correctly handles fields wrapped in quotes that contain commas, line breaks, or special characters.
Multiple Output Formats
Choose between pretty-printed JSON for readability or compact JSON for smaller file sizes.
Large File Support
Handles CSV files up to 10MB in size, processing thousands of rows efficiently in your browser.
Browser-Based Processing
All conversion happens on your device. CSV data never leaves your computer, which matters for sensitive business data or customer information.
CSV Format Requirements
The converter works with standard CSV files that follow these conventions:
Consistent Delimiters: Each row must use the same delimiter throughout the file. Mixing commas and semicolons in different rows will cause parsing errors.
Quoted Fields: Fields containing the delimiter character must be wrapped in double quotes. For example: "Smith, John",35,Engineer. Fields without special characters don't need quotes.
Escaped Quotes: To include a quote character inside a quoted field, double it. For example: "He said ""hello""" becomes: He said "hello".
Line Breaks: The tool handles Windows (CRLF), Unix (LF), and Mac (CR) line endings. Multi-line fields must be enclosed in quotes.
Output Format Options
When headers are present, the converter creates an array of objects where each CSV column becomes an object property:
CSV: name,age,city
John,30,Boston
JSON: [{"name":"John","age":"30","city":"Boston"}]
Without headers, the converter creates an array of arrays representing raw row and column data.
Privacy and Security
This converter operates entirely within your browser using JavaScript. When you upload a CSV file or paste data, nothing is transmitted to any server. The file is read and processed locally on your device.
This is important when working with customer lists, financial data, or internal business information. Since conversion is client-side, there's no risk of exposing sensitive data through network transmission.
The tool doesn't store your data in browser cache or local storage. When you close the tab, all CSV and JSON data is cleared from memory.
Common Questions
The tool automatically detects common delimiters including commas, semicolons, tabs, and pipes. It analyzes your data and selects the appropriate separator without requiring manual configuration.
Fields containing commas should be wrapped in double quotes. The parser recognizes quoted fields and treats the entire contents as a single value, even if it contains the delimiter character.
No. All conversion happens in your browser. The CSV file is read locally on your device and never sent anywhere.
This tool converts CSV to JSON only. For the reverse operation, you would need a JSON to CSV converter which is a different tool.
When "First row contains headers" is checked, column names from the first row become object property names in the JSON. When unchecked, the tool treats all rows as data and creates an array of arrays instead of an array of objects.
No, this tool only works with CSV text files. To convert Excel data, first export your spreadsheet as CSV from Excel, then use this tool to convert the CSV to JSON.