Development, data analysis and spreadsheets constantly need format swaps: code emits JSON, a colleague wants Excel, an import tool expects CSV. This tool converts tabular data between all three, entirely in your browser with no upload — safe even for data with personal information.
How to use
Paste JSON or CSV into the input box, or upload a .json / .csv / .xlsx file.
Click To JSON, To CSV or To Excel.
JSON/CSV results can be copied or downloaded; Excel downloads an .xlsx directly.
Common use cases
Hand a JSON API response to a colleague who only uses Excel.
Turn a spreadsheet CSV export into JSON your code can parse.
Package database query results into an .xlsx report.
Clean up columns before importing into another system.
Frequently Asked Questions
Is my data uploaded?
No. All conversion runs locally in your browser (using SheetJS). The data you paste or the file you upload is never sent to a server or stored.
What JSON shape is supported?
It works best with an array of objects — each element is a row and its properties are columns, e.g. [{"name":"A","age":1}, …]. A single object is treated as one row.
How does Excel input and output work?
Input: upload an .xlsx file and the first sheet is read. Output: choosing "Excel" downloads an .xlsx file directly. JSON and CSV can be pasted as text or uploaded.
Can it handle large files?
Yes, as long as it fits in your browser memory. Tens of thousands of rows are usually fine; for very large files, use a desktop browser.
