Free Excel for the Web with a Microsoft account; full app on Microsoft 365
Custom domains
n/a
Note
The spreadsheet incumbent — Microsoft Excel for the Web is free forever with a Microsoft account (browser-only, core features, auto-save to OneDrive 5 GB), but the full desktop app with Power Query, Power Pivot, advanced charts, and add-ins needs Microsoft 365. Microsoft 365 Personal from ~$6.99/mo includes the desktop Excel + Word + PowerPoint + 1 TB OneDrive. The most powerful spreadsheet, but the desktop version is paid — free Excel for the Web is the no-cost option.