What delimiter types are supported?

The tool supports comma (,), semicolon (;), tab (\t), and pipe (|) delimiters. Commas are the standard CSV format, but many European systems use semicolons. Tab-separated values (TSV) are common for data exports, and pipes are used when data contains commas. The tool auto-detects delimiters in most cases.

How are CSV headers handled?

If your CSV has a header row (column names in the first row), enable the "Has Headers" option. The headers become JSON object keys. Without headers, the tool generates generic keys (column1, column2, etc.) or outputs arrays. Proper header handling is crucial for meaningful JSON output.

Can I convert JSON back to CSV?

Yes. The tool supports bidirectional conversion. JSON arrays of objects convert cleanly to CSV with object keys becoming column headers. Nested JSON objects are flattened using dot notation (e.g., user.name becomes a column). Complex nested structures may require manual adjustment.

What happens to empty cells in CSV?

Empty CSV cells convert to empty strings ("") in JSON by default. Some tools convert them to null values. If your application requires null instead of empty strings, you will need to post-process the JSON or use data type inference if the tool provides that option.

How are data types handled during conversion?

CSV is a text format with no inherent data types. By default, all values convert to strings in JSON. Some tools offer automatic type inference, detecting numbers (123 becomes integer), booleans (true/false), and null values. For precise type control, manually edit the JSON after conversion or use a schema-aware import tool.

Is there a file size limit for CSV conversion?

Browser-based tools typically handle CSV files up to 10-50MB depending on device memory. Very large files (100,000+ rows) may cause performance issues or browser crashes. For enterprise-scale CSV processing (millions of rows), consider server-side tools or command-line utilities like csvkit or jq.

CSV to JSON Converter - Free Online Tool

How to Convert CSV to JSON

Paste your CSV data or upload a CSV file
Configure delimiter (comma, semicolon, tab) and header options
Click convert to transform CSV to JSON format
Download JSON file or copy the output

Why Use Our CSV to JSON Converter?

Custom Delimiters: Support for comma, semicolon, tab, and custom separators
Header Detection: Automatically uses first row as JSON keys
Bidirectional: Convert CSV to JSON and JSON back to CSV
Array or Object Output: Choose between JSON array or object format
100% Free: No registration or file size limits
Privacy First: All conversions happen in your browser

When to Use JSON vs CSV

CSV is ideal for simple tabular data that needs to open in Excel or Google Sheets. Each row represents one record, and columns are consistent across all rows.

JSON is better for nested or hierarchical data, API payloads, and application configuration. JSON supports arrays, objects, and multiple data types (strings, numbers, booleans, null).

Common use cases for CSV to JSON conversion: importing data to NoSQL databases, preparing API request bodies, migrating from spreadsheets to web applications, and integrating with JavaScript frameworks that expect JSON input.

Privacy & Security

Your CSV and JSON data never leaves your device. All conversion happens client-side in your browser using JavaScript. No files are uploaded to servers, and no data is stored or logged.