Microsoft 365 vs Outlook Web App
Head-to-head usage across the sites we track.
Top sites by authority
Microsoft 365 · Outlook Web App · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank scores 0 to 10 from the open web link graph; 9+ covers only a few hundred domains worldwide.
By country
Microsoft 365 · Outlook Web App · share of sites in each country using one or the other
United States
452,995
2,737
United Kingdom
171,261
1,378
Germany
135,089
1,246
Canada
108,446
1,160
India
100,575
1,532
Netherlands
100,183
953
France
93,767
1,097
Australia
91,309
647
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Microsoft 365 | Outlook Web App |
|---|---|---|
| LCP | 1.8 s | 1.7 s |
| INP | 75 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 800 ms | 700 ms |
Median site's p75 values from the Chrome UX Report, Sep 2026. Lower is better; green meets Google's "good" threshold. This describes the sites that use each technology, not the technology's own overhead.
Sites that switched
Domains that dropped one technology and adopted the other within about a year, data nobody else gives away free.
Outlook Web App to Microsoft 365
| Domain | When |
|---|---|
| igg.go.ug | Jul 2026 |