How to Open XLSX Spreadsheet Files Online Privately

Work through this in order

1. Save the XLSX file locally and avoid enabling macros from strangers.
2. Select the XLSX Spreadsheet Viewer and choose the workbook.
3. Review detected sheets and the first visible rows.
4. Check whether formula cells have cached values; the viewer never calculates them.
5. Open in a spreadsheet editor if you need pivot tables, styles or full formulas.

Use the matching tool

Inspect a local copy with XLSX Spreadsheet Viewer. After the check, save or repair files only using trusted software that supports the format.