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 9+
64
0
Open Page Rank 8+
1,806
11
Open Page Rank 7+
10,464
29
Open Page Rank 6+
24,469
50
Open Page Rank 5+
49,442
68
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
513,561
3,011
United Kingdom
192,504
1,538
Germany
149,868
1,446
Canada
123,911
1,313
India
114,600
1,731
Netherlands
111,248
1,098
France
109,542
1,326
Australia
104,165
732
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 | 50 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 700 ms | 700 ms |
Median site's p75 values from the Chrome UX Report, Jun 2026. Lower is better; green meets Google's "good" threshold. This describes the sites that use each technology, not the technology's own overhead.