Paste JSON above to see a preview
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About this tool
Paste any JSON, choose how to flatten nested objects and arrays, preview the resulting table in your browser, then download it as an xlsx workbook. Numbers, booleans and dates keep their native types; nulls follow your chosen empty-value rule. Everything runs locally — your data never leaves your device.
How to use
- Paste your JSON into the input box.
- Pick the array strategy, object flattening depth, empty-value rule, and whether to detect dates.
- Preview the flattened table on the right.
- Click Export xlsx to download the workbook.
Is my JSON uploaded anywhere?
No. Parsing, flattening and xlsx generation all happen in your browser, so your data never leaves your device.
How are nested objects and arrays handled?
Nested objects can be flattened into dot-path columns (a.b.c). For nested arrays you choose between expanding them into multiple rows, joining elements with a comma, or serializing the whole array into one cell.
Does exporting a huge JSON slow down the preview?
Only the first 1000 rows are rendered in the preview for performance. The export still uses the complete data, so no rows are lost.