Customer.io vs Klaviyo
Head-to-head usage across the sites we track.
Top sites by authority
Customer.io · Klaviyo · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank 9+
1
17
Open Page Rank 8+
19
117
Open Page Rank 7+
78
456
Open Page Rank 6+
129
1,239
Open Page Rank 5+
195
3,036
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 · Klaviyo · share of sites in each country using one or the other
United States
1,038
103,547
United Kingdom
545
40,783
Canada
553
33,265
Australia
443
30,331
Germany
508
26,133
France
439
23,908
India
649
22,437
Spain
384
16,738
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Customer.io | Klaviyo |
|---|---|---|
| LCP | 2.4 s | 1.6 s |
| INP | 125 ms | 100 ms |
| CLS | 0 | 0 |
| TTFB | 800 ms | 500 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.