Online CSV & JSON Converter

Convert between CSV and JSON with custom delimiters and header control. 100% private, all processing in your browser

Two-Way Convert

CSV to JSON and JSON to CSV

Privacy First

Your data never leaves your device

Flexible Delimiters

Comma, semicolon, tab, or pipe

Header Toggle

Include or skip the header row

Converter Settings

Frequently Asked Questions

How does the CSV/JSON converter work?

In CSV to JSON mode, each row becomes an object keyed by the header row (or by column index). In JSON to CSV mode, an array of objects is serialized into rows with the object keys as the header.

Will my data be uploaded to a server?

No. All conversion is done locally in your browser. Your data never leaves your device, fully protecting your privacy.

Which delimiters are supported?

Comma (,), semicolon (;), tab, and pipe (|). Pick the one that matches your data, common in European spreadsheets that use semicolons.

What does the header toggle do?

When enabled, the first CSV row (or JSON object keys) is treated as field names. Disable it to use generic column names like col1, col2 for headerless data.

Is this tool free to use?

Completely free. This is a pure frontend online tool - no registration required, no payment needed, just open and use.

What JSON shapes are supported?

For JSON to CSV, provide an array of objects (or a single object). Nested objects and arrays are stringified into a single cell, while top-level keys become columns.