Is my data uploaded anywhere?

No. All parsing, preview, and export happen locally in your browser. Your JSON is never sent to a server.

What is the file size limit?

5 MB per input. Larger inputs are rejected before parsing.

Are nested objects flattened?

Yes. Nested objects are flattened into dot-path columns such as userInfo.contact.email.

Are nested arrays expanded into new tables?

No. Arrays inside a row are written to a single cell as a JSON string and are not expanded.

What is the difference between CSV and XLSX?

CSV is a single-table text file. XLSX is a spreadsheet workbook; multiple tables can be exported as separate sheets in one file.

CSV vs XLSX: Which Format to Choose

Practical differences between CSV and XLSX exports and when to use each.

Both formats are available for download, but they serve different needs. Here is how to pick the right one.

When to choose CSV

CSV is a plain-text, single-table file. It is universally supported, opens instantly in any spreadsheet app or text editor, and is ideal for piping into scripts, databases, or version control. Choose CSV when you need portability and a single table.

When to choose XLSX

XLSX is a binary spreadsheet workbook. It can hold multiple sheets in one file, preserves types better, and feels native in Excel. Choose XLSX when you have several tables and want them bundled, or when you will continue editing in a spreadsheet.

Exporting everything at once

If your JSON produced multiple tabs, "Download all (XLSX)" writes one workbook with one sheet per table — handy for sharing a complete dataset in a single file.