JSON to Excel Converter

Absolutely. The JSON to Excel Converter runs 100% client-side inside your web browser. No data is sent to any server, stored online, or logged. All parsing, flattening, and Excel workbook compilation happen in your local device's memory using JavaScript, ensuring your records remain completely private.

By checking 'Flatten nested', the conversion engine recursively expands child objects into columns using a separator of your choice (e.g. dot or underscore). For example, { "contact": { "phone": "123" } } produces a column named contact.phone. Key paths are traversed down to the leaf values.

When enabled, the top row containing the column names will be locked in place. When you open the exported .xlsx spreadsheet inside Microsoft Excel or Google Sheets, the header will remain visible at the top as you scroll down through large datasets.

Yes. If 'Preserve data types' is checked, numeric strings are stored as native Excel number cells, booleans as boolean cells, and null values as blank cells. If unchecked, all data cells are written as text strings. Preserving types is highly recommended if you plan to write formulas (like SUM, AVERAGE) in your sheet.

If you check 'Pretty headers', nested column keys like contact.first_name are transformed into neat display labels such as Contact First Name. This makes the spreadsheet look professional and easy to read for business analysts and stakeholders.

Yes, the tool is optimized to process files up to 10MB in size. For large arrays with hundreds of elements, the table preview uses a virtual scrolling list, which only renders visible rows in the browser DOM to prevent lagging, memory leaks, and browser crashes.