CSV to JSON Converter - Free Online CSV to JSON Array Tool

How to Use This CSV to JSON Transformation Tool

Paste your CSV data (with headers in row 1) into the input.
The tool automatically detects the delimiter (comma or tab) and parses the headers.
The CSV to JSON array appears in the output - each row becomes an object keyed by column name.
Use the options to output a flat array or a nested structure with a custom root key.

CSV to JSON Converter provides a streamlined way to transform spreadsheet data into a format suitable for web APIs and modern applications. Converting CSV to JSON is a daily task for developers working with data exports, integrations, and database migrations. This utility parses the header row as object keys and maps each subsequent row to a JSON data converter object - handling quoted fields and special characters automatically.

Convert CSV to JSON Online Instantly

Our tool simplifies the mapping process by given a CSV with headers "id, name, email" and two data rows, the output is an array of objects: [{"id":"1","name":"Alice","email":"a@example.com"},{"id":"2",...}]. This spreadsheet to json tool defaults to string values to preserve raw data, but offers optional type inference for numbers and booleans. It's the perfect solution for quick data transformations without writing custom scripts.

Automatic header detection from row 1
Handles quoted fields, embedded commas, and newlines in values
Optional type inference: numbers and booleans converted from strings
Pretty-printed or compact JSON output

Frequently Asked Questions

What happens if a row has fewer columns than the header?

Missing fields are included as null in the output object so the key is present in every object - making downstream JSON processing predictable.

What if my CSV has no header row?

Enable the "No header row" option. Column keys become positional: "col1", "col2", etc. You can rename them in the output options.

How are numeric values handled?

By default, all CSV values are output as JSON strings. Enable "numeric inference" to convert unquoted, valid numeric values to JSON numbers. This is off by default because CSV numbers that look like IDs or codes (leading zeros, phone numbers) should remain strings.

Can I convert the output back to CSV?

Use the JSON to CSV tool (or CSV to JSON's reverse mode). The round-trip is lossless as long as all values are strings and the column order is preserved.

See also JSON to CSV and JSON Formatter to further manipulate your data once you've used this CSV to JSON Converter.