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+
592
6
Open Page Rank 7+
2,377
7
Open Page Rank 6+
5,007
7
Open Page Rank 5+
9,296
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
80,356
81
United Kingdom
32,182
43
India
24,828
263
Canada
25,031
39
Germany
19,175
42
Australia
18,734
29
France
17,309
43
Netherlands
16,271
27
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Mailgun | SmtpJS |
|---|---|---|
| LCP | 1.8 s | 2.4 s |
| INP | 75 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 700 ms | 850 ms |
Median site's p75 values from the Chrome UX Report, Aug 2026. Lower is better; green meets Google's "good" threshold. This describes the sites that use each technology, not the technology's own overhead.