Email marketing impact WordPress sites
Performance impact by email_marketing provider.
1
At a glance the headline numbers for Email marketing impact
Performance impact by email_marketing provider.
4
Providers ranked
After min-sites filter
3,152
Sites in sample
Combined across all items
0.08
Best CLS (p75)
HubSpot
The State of Web Vitals · October 2026 · WordPress sites (63,295) · desktop field datacorewebvitals.io/state-of-cwv
2
The ranking sorted by CLS at p75, fastest first
| # | Provider | CLS p75 | Passing | Sites | |
|---|---|---|---|---|---|
| 1 | HubSpot | 0.08 | 80.5% | 1,071 | |
| 2 | Klaviyo | 0.09 | 79.2% | 271 | |
| 3 | ActiveCampaign | 0.10 | 75.7% | 242 | |
| 4 | Mailchimp | 0.11 | 74.7% | 1,568 |
The State of Web Vitals · October 2026 · WordPress sites (63,295) · desktop field datacorewebvitals.io/state-of-cwv
3
Passing CLS per provider which group passes the CLS most often
ProviderSitesPassing CLSp75
HubSpot 1.7% 1,071 0.08
Klaviyo 0.4% 271 0.09
ActiveCampaign 0.4% 242 0.10
Mailchimp 2.5% 1,568 0.11
Good Needs Improvement Poor Sorted best-passing first · median colored by its own rating · pass = good CLS (0.1 at p75) · one value per site
81% of HubSpot sites pass CLS. Mailchimp trails 6 points behind. computed
The State of Web Vitals · October 2026 · WordPress sites (63,295) · desktop field datacorewebvitals.io/state-of-cwv
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All five vitals at once the whole category without toggling - cell is the pass rate, small number the p75
LCP
INP
CLS
FCP
TTFB
Mailchimp 2.5%
623.0s
10063ms
750.11
542.5s
192.1s
HubSpot 1.7%
722.6s
10066ms
810.08
652.1s
321.8s
Klaviyo 0.4%
573.2s
9975ms
790.09
502.6s
212.3s
ActiveCampaign 0.4%
692.7s
10068ms
760.10
592.3s
281.9s
60%95%+ passing Cell: pass rate, small number = p75 · faded rows: under 100 sites
One row per provider, one column per vital - the cell is the share of sites passing, the small number the p75. No toggling needed to see where the category actually differs.
HubSpot leads on CLS: 81% of its sites pass. Mailchimp trails at 75%. computed
The State of Web Vitals · October 2026 · WordPress sites (63,295) · desktop field datacorewebvitals.io/state-of-cwv
Related signals Font services (4) → Session recording (11) → CMS (17) → Search (6) → 203,892 crawled sites with Chrome field data, representing millions of real page loads · How we measured
203,892 crawled sites with Chrome field data, representing millions of real page loads. How we measured.