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
59
Open Page Rank 8+
18
871
Open Page Rank 7+
72
3,844
Open Page Rank 6+
126
8,214
Open Page Rank 5+
192
15,705
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
883
142,004
United Kingdom
487
65,019
Canada
478
42,102
India
574
41,567
Australia
394
32,722
Germany
422
31,989
Italy
315
31,919
France
370
31,178
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, 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.