Customer.io vs MailChimp
Head-to-head usage across the sites we track.
Top sites by authority
Customer.io · MailChimp · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank 9+
1
55
Open Page Rank 8+
19
881
Open Page Rank 7+
78
3,928
Open Page Rank 6+
129
8,381
Open Page Rank 5+
195
16,023
Open Page Rank scores 0 to 10 from the open web link graph; 9+ covers only a few hundred domains worldwide.
By country
Customer.io · MailChimp · share of sites in each country using one or the other
United States
1,038
161,030
United Kingdom
545
74,844
Canada
553
48,970
India
649
47,917
France
439
37,876
Australia
443
37,236
Italy
351
37,051
Germany
508
36,354
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Customer.io | MailChimp |
|---|---|---|
| LCP | 2.4 s | 2 s |
| INP | 125 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 800 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.