CSV to JSON Converter
CSV ⇆ JSON Converter
Convert between CSV and JSON formats. Supports custom delimiters and header options.
Developer Code Examples
Python (Most Popular)
import pandas as pd
# Convert CSV to JSON
df = pd.read_csv('data.csv')
json_result = df.to_json(orient='records')
print(json_result)
# Convert JSON to CSV
df = pd.read_json('data.json')
df.to_csv('output.csv', index=False)
JavaScript
// Using PapaParse library
// CSV to JSON
Papa.parse(csvString, {
complete: function(results) {
console.log(JSON.stringify(results.data));
}
});
// JSON to CSV
const csv = Papa.unparse(jsonData);
Pro Tip: For quick conversions without coding, use our online tool above. It handles edge cases automatically.
CSV Format Reference
Basic Format
name,email,age John,john@test.com,30 Jane,jane@test.com,25
Quoted Fields
"Name","Description" "Product A","Has a, comma" "Product B","Has ""quotes"""
Common Delimiters
,- Comma (default);- Semicolon (EU)\t- Tab (TSV)|- Pipe
Escape Rules
- Use quotes for fields with commas
- Double quotes inside:
"" - Newlines must be quoted
How to Use This Tool
- Choose Conversion Direction: Select "CSV to JSON" to convert spreadsheet data to JSON format, or "JSON to CSV" to flatten JSON objects into tabular format. Each direction has specific options.
- Paste Your Data: Enter CSV data with rows separated by newlines and columns by your chosen delimiter, or JSON data as an array of objects. Click "Load Sample" to see expected formats.
- Configure Options: For CSV: select delimiter (comma, semicolon, tab, pipe), indicate if the first row is headers, and enable whitespace trimming. For JSON: choose whether to include nested objects.
- Click Convert: The converted output appears below. CSV becomes a JSON array of objects with header names as keys. JSON becomes CSV with object keys as column headers. Copy the result for your use.
Technical Details
CSV (Comma-Separated Values) is a plain-text tabular format where rows are lines and columns are delimiter-separated values. The first row typically contains headers. Values with commas, quotes, or newlines must be quoted and internal quotes escaped by doubling (""). The RFC 4180 standard defines the format, though implementations vary.
JSON (JavaScript Object Notation) represents structured data with objects and arrays. For CSV conversion, JSON should be an array of objects with consistent keys. Nested objects are flattened using dot notation (address.city becomes "address.city" column) or serialized as strings. Empty values become empty strings in CSV or null in JSON. When converting JSON to CSV, only the first object's keys define columns—subsequent objects with additional keys may lose data.
Common Mistakes to Avoid
- Missing or Inconsistent Headers: CSV without a header row produces objects with numeric keys (0, 1, 2). If rows have different column counts, data misaligns. Ensure all rows have the same number of fields as the header.
- Nested JSON Losing Structure: Deeply nested JSON objects can't map directly to flat CSV. Child objects become stringified JSON in cells, or must be flattened with dot-notation column names. Plan your structure before converting.
- Delimiter Conflicts: If your data contains commas and you use comma as delimiter, values must be quoted. A common bug: exporting from Excel with semicolon delimiter in some locales, then importing as comma-delimited elsewhere.
Frequently Asked Questions
How do I convert CSV to JSON in Python?
Use pandas library - `pd.read_csv('file.csv').to_json('file.json')`. For quick conversions without coding, use our online tool above.
What is the difference between CSV and JSON formats?
CSV is tabular data (rows/columns), best for spreadsheets. JSON is hierarchical (objects/arrays), best for APIs and web applications.
Can I convert nested JSON to CSV?
Yes, but nested objects will be flattened. Our tool handles basic nesting with dot notation (e.g., `user.address.city`).
Is CSV to JSON conversion secure?
Absolutely. All processing happens locally in your browser. No data is sent to our servers.