Text & code · runs locally
Convert spreadsheets to CSV or JSON
Excel in, clean data out. Pick the sheets, choose CSV or JSON, and keep dates under control.
Runs on your device
No uploads, ever
Free, no account
- 1Drop a spreadsheet or CSV
XLSX, XLS, ODS and CSV all open here. JSON input lives in the separate JSON to CSV tool.
- 2Choose the sheet and date style
Convert one sheet or all of them, with dates as ISO 8601, the workbook's display format, or the raw Excel serial.
- 3Download
One CSV or JSON per sheet, or tick "One JSON file" to bundle every chosen sheet under one key.
Questions people actually ask
Are formulas evaluated?
Cached values are used — what you last saw in Excel is what converts. The formulas themselves live on in the original file.
My dates changed format!
For workbook date cells, choose ISO 8601, the workbook's display format, or the raw Excel serial. CSV input stays as plain text, so its dates and leading zeros are never guessed.