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
58
Open Page Rank 8+
17
863
Open Page Rank 7+
71
3,810
Open Page Rank 6+
122
8,097
Open Page Rank 5+
186
15,491
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
868
140,200
United Kingdom
489
64,810
Canada
467
41,963
India
564
40,362
Italy
312
33,400
Netherlands
321
31,497
Australia
363
31,343
Spain
346
31,220
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Customer.io | MailChimp |
|---|---|---|
| LCP | 2.4 s | 1.9 s |
| INP | 125 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 800 ms | 900 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.