CSV to JSON Converter
Convert CSV to JSON and JSON to CSV online. Free tool to transform data between CSV and JSON formats with proper parsing and validation.
Tool Purpose & Audience
The CSV to JSON Converter transforms comma-separated values (CSV) into structured JSON objects, and converts JSON arrays back to CSV format. It handles headers, delimiters, quoted fields with embedded commas, and nested value parsing — the full complexity of real-world CSV data.
Data analysts, web developers, API integrators, and database administrators use this tool when moving data between spreadsheets, databases, REST APIs, and configuration files. CSV is the export format of Excel, Google Sheets, and most databases; JSON is the standard input format for web APIs and modern applications.
Real-World Use Cases
- Spreadsheet to API data: Export data from Google Sheets or Excel as CSV, convert to JSON, then POST it to a REST API endpoint that expects JSON-formatted data.
- Database migration: Many databases export query results as CSV. Converting to JSON enables importing into document databases (MongoDB, Firebase) that use JSON-based document storage.
- Frontend data loading: Prototyping a web app with static data? Convert a CSV spreadsheet to a JSON array and import it directly as mock data in your JavaScript application.
- Reporting and analytics: Convert JSON API responses back to CSV for importing into Excel or Google Sheets for business analysis by non-technical stakeholders.
Practical Input → Output Examples
1. CSV with headers to JSON array
Input: "name,age,city\nAlice,30,London\nBob,25,Paris"
Output: [{"name":"Alice","age":"30","city":"London"},{"name":"Bob","age":"25","city":"Paris"}]
Each row becomes a JSON object with the header row values as keys — the standard format for API payloads and data processing.
2. JSON array back to CSV
Input: [{"product":"Widget","price":9.99,"qty":100}]
Output: "product,price,qty\nWidget,9.99,100"
JSON converted to CSV — ready to import into Excel, Google Sheets, or any data analysis tool that accepts CSV.
3. CSV with quoted fields (embedded commas)
Input: 'name,address\n"Smith, John","42 Oak St"'
Output: [{"name":"Smith, John","address":"42 Oak St"}]
Quoted CSV fields containing commas are correctly parsed as single values — essential for address and name data.
Common Mistakes & Misunderstandings
All values start as strings unless parsed: CSV has no type system — every value is a string. "30" in a CSV is the string "30", not the number 30. Enable "Auto-detect types" if your tool offers it, or parse types in your downstream code.
Delimiter variations: Standard CSV uses commas, but some regional variants use semicolons (;), tabs (\t), or pipes (|). If your conversion produces garbled output, check which delimiter the source file actually uses and set the tool accordingly.
Encoding issues with Excel: Excel exports CSV in Windows-1252 encoding by default (not UTF-8) on Windows systems. If your CSV contains special characters that appear as garbled symbols after conversion, re-save the CSV as UTF-8 first.
Nested JSON doesn't convert to flat CSV cleanly: If your JSON has nested objects ({ "address": { "city": "London" } }), converting to CSV produces nested structure in a single cell or fails entirely. Only flat (single-level) JSON arrays convert cleanly to CSV.
How do I convert CSV to JSON?
Paste your CSV data into the input area, select 'CSV to JSON' mode, and click the Convert button. The tool will parse your CSV and generate properly formatted JSON output.
How do I convert JSON to CSV?
Paste your JSON data into the input area, select 'JSON to CSV' mode, and click the Convert button. The tool will convert your JSON array or object into CSV format with proper headers.
What CSV formats are supported?
The tool supports standard CSV format with comma separators, quoted fields, and escaped characters. It can handle headers and various data types including strings, numbers, and booleans.
Can I upload CSV or JSON files?
Yes, you can upload CSV or JSON files using the Upload button. The tool will automatically detect the file type and load the content for conversion.
How do I download the converted data?
After conversion, use the Download button to save the result as a .csv or .json file. You can also copy the converted data to your clipboard using the Copy button.
Is my data secure when using this converter?
Yes, all conversions are performed locally in your browser. Your data is never sent to our servers, ensuring complete privacy and security.