Runs locally · Zero uploads

CSV to JSON Converter

Drop a CSV file or paste data. Preview the parsed table before converting to JSON.

— or drop a CSV file —

How it works

CSV (Comma-Separated Values) is the most widely used flat-file format for tabular data — exported from Excel, Google Sheets, databases, and analytics tools. JSON (JavaScript Object Notation) is the standard for web APIs and modern applications. This tool bridges the two formats by parsing CSV rows into an array of JSON objects, using the first row as column headers.

Before converting, the tool renders a live table preview so you can verify that columns are aligned correctly. This is especially useful when your CSV uses a non-standard delimiter (semicolons are common in European Excel exports, tabs in TSV files, pipes in legacy systems). Select the correct delimiter and the preview updates instantly.

The parser handles quoted fields, escaped quotes, newlines within fields, and mixed line endings (CRLF, LF, CR). It processes the file entirely in your browser — your spreadsheets, customer data, and financial records never leave your device.

For batch processing or programmatic access, the same conversion is available through the Bytario API with streaming support for files up to 500 MB.

Verify it yourself. Open DevTools → Network → run a conversion. The only requests you'll see are the page assets — your file never leaves this tab.

FAQ

Does this handle CSV files with quoted fields?

Yes. Fields wrapped in double quotes are parsed correctly, including fields that contain the delimiter character, newlines, or escaped quotes ("").

What if my CSV has no header row?

The tool uses the first row as column headers. If your file has no headers, add a header row first, or the first data row will be treated as keys (producing {"Alice":"Bob","30":"25"} etc.).

Can I convert a TSV (tab-separated) file?

Yes. Select "Tab" from the delimiter dropdown and the parser will split on tab characters instead of commas.

How large a CSV can I convert?

The converter runs in your browser's memory. Files up to ~50 MB work well on most devices. For larger files, use the Bytario API which supports streaming.

Why does my CSV produce unexpected columns?

The most common cause is a delimiter mismatch. European Excel exports often use semicolons instead of commas. Try switching the delimiter dropdown. The live preview will show whether columns are parsed correctly.