Mailgun vs SmtpJS
Head-to-head usage across the sites we track.
Top sites by authority
Mailgun · SmtpJS · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank 9+
32
4
Open Page Rank 8+
587
6
Open Page Rank 7+
2,395
7
Open Page Rank 6+
5,020
7
Open Page Rank 5+
9,287
9
Open Page Rank scores 0 to 10 from the open web link graph; 9+ covers only a few hundred domains worldwide.
By country
Mailgun · SmtpJS · share of sites in each country using one or the other
United States
88,542
99
United Kingdom
36,088
47
Canada
28,317
44
India
27,650
313
Germany
21,441
51
Australia
20,734
39
France
20,584
48
Netherlands
18,415
32
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Mailgun | SmtpJS |
|---|---|---|
| LCP | 1.8 s | 2.5 s |
| INP | 75 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 700 ms | 900 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.