Data tools
Convert local CSV files into XLSX spreadsheets. Choose how numbers are stored, preserve identifiers and download without uploading your data.
Data tools for local spreadsheet files
This section currently contains one converter: CSV to Excel. It is useful when you have exported records from another app and need a workbook you can open in a spreadsheet editor. Choose the files first, then decide whether ordinary numeric values should become numbers or whether every cell should stay text. The converter also reads tab-separated files. Comma, semicolon and tab separators can be detected automatically or selected explicitly. Files remain on your device throughout the conversion, and each input produces a separate download rather than merging unrelated tables into one workbook.
Identifiers, headers and worksheet limits
Leading zeros and integers longer than 15 digits remain text so an identifier is not silently shortened. Dates stay text too. You can make the first row bold and keep it visible while scrolling by enabling the header option. A worksheet can contain up to 1,048,576 rows and 16,384 columns; files beyond those limits report an error. Output is XLSX, with no legacy XLS export, formula inference or malformed-file repair. UTF-8 is tried first and a Windows-1252 fallback is shown in the result. Large files use a background worker but still depend on available device memory.
