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Client-side ProcessingUpdated 2026-02-11Report issue

Runs fully in your browser. Inputs stay on your device. See recent fixes on changelog.

CSV to JSON File Converter

Convert CSV files to JSON format with header mapping.

FreeRuns in browsercsv to jsoncsv to json converter
Cmd/Ctrl+Enter Primary actionCmd/Ctrl+Shift+L Load sampleCmd/Ctrl+Shift+X Clear/resetCmd/Ctrl+Shift+C Copy result

About CSV to JSON File Converter

Convert CSV files to JSON format with header mapping. Convert CSV files to JSON online for free. Automatic header detection and column-to-key mapping with support for nested objects. Download or copy JSON output. Accurately converts complex nested data structures while preserving hierarchy, types, and special characters. Provides clear error messages for malformed input to help you troubleshoot quickly. Everything runs client-side in your browser for maximum speed and privacy — no data is sent to any server, and no signup is required.

Related tools: JSON to CSV File Converter, CSV to XML Converter, CSV to HTML Table

How to Use CSV to JSON File Converter

  1. Paste your source data into the input area.
  2. Select the target format from the available options.
  3. Click Convert and copy the formatted output.

Frequently Asked Questions

What is CSV to JSON File Converter?
Convert CSV files to JSON online for free. Automatic header detection and column-to-key mapping with support for nested objects. Download or copy JSON output.
Are comments preserved during conversion?
Comment handling depends on the source and target formats. Formats that support comments (like YAML and TOML) will have them parsed, but since most data interchange formats like JSON do not support comments, they may be stripped during conversion.
What happens with invalid input?
The tool validates your input before conversion and displays clear error messages if the data is malformed. This helps you identify and fix syntax issues before attempting the conversion.
Can I convert between nested formats?
Yes, deeply nested and complex data structures are fully supported. The converter preserves the hierarchy, arrays, and key-value pairs from your source format and maps them accurately into the target format.
Is CSV to JSON File Converter free to use?
Yes, all format conversions are free and unlimited. No account is required, and the tool works entirely in your browser.
Is my data safe when using CSV to JSON File Converter?
Yes, your data stays on your device. The conversion runs entirely in your browser, and no data is uploaded to any server.

Related Tools

JSON to CSV File Converter
Convert JSON arrays to CSV format with column headers.
CSV to XML Converter
Convert CSV data to well-formed XML documents.
CSV to HTML Table
Convert CSV data to HTML table markup.