How to convert excel to json for react seed data
- Step 1Upload the spreadsheet — Drop the .xlsx or .xls file onto the converter. The first row must contain column headers — they become the object keys for every JSON record in the output array.
- Step 2Enable type inference — Leave 'Infer types' on so numeric IDs, prices, and boolean flags arrive as native JavaScript values. Turn it off only if your downstream code expects every field as a string.
- Step 3Choose array root or named key wrapper — Leave the output as a bare array for direct useState([...]) or useReducer imports, or wrap it in a named key such as { products: [...] } to match a Zustand store slice.
- Step 4Download and import — Save the .json file into your project's public/ or data/ folder. Import it with import data from './products.json' (TypeScript) or read it with fs.readFileSync inside a Next.js getStaticProps function.
Frequently asked questions
Can I include data from multiple sheets?+
The converter processes the active (first) sheet by default. To convert a different sheet, move it to the first position in Excel or Google Sheets before exporting, or use the sheet selector if your .xlsx contains named sheets. Convert each sheet separately and import each resulting JSON file independently.
Will merged cells produce malformed JSON keys?+
Merged cells export as an empty string in every sub-cell except the top-left one in most Excel exports. Unmerge cells before converting, or handle empty strings as null in your React component using a mapping function after import.
Does the .xlsx file leave my machine?+
No. The xlsx parser runs entirely in your browser. Spreadsheet contents — including any customer data, pricing, or proprietary product information — are never sent to JAD Apps servers.
Privacy first
Conversion runs locally in your browser. No file is uploaded — only metadata counters are saved for signed-in dashboard stats.