1
At a glance the headline numbers for Email marketing impact
Performance impact by email_marketing provider.
5
Providers ranked
After min-sites filter
10,529
Sites in sample
Combined across all items
0.02
Best CLS (p75)
Mailchimp
The State of Web Vitals · October 2026 · 203,892 crawled sites · phone field datacorewebvitals.io/state-of-cwv
2
The ranking sorted by CLS at p75, fastest first
| # | Provider | CLS p75 | Passing | Sites | |
|---|---|---|---|---|---|
| 1 | Mailchimp | 0.02 | 88.3% | 3,524 | |
| 2 | Klaviyo | 0.03 | 89.8% | 3,157 | |
| 3 | ActiveCampaign | 0.04 | 85.6% | 474 | |
| 4 | HubSpot | 0.04 | 85.6% | 3,310 | |
| 5 | Salesforce Marketing Cloud | 0.08 | 79.4% | 64 |
The State of Web Vitals · October 2026 · 203,892 crawled sites · phone field datacorewebvitals.io/state-of-cwv
3
Passing CLS per provider which group passes the CLS most often
ProviderSitesPassing CLSp75
Braze 0% 24 0.08
Klaviyo 1.5% 3,157 0.03
Mailchimp 1.7% 3,524 0.02
HubSpot 1.6% 3,310 0.04
ActiveCampaign 0.2% 474 0.04
Marketo 0% 42 0.03
Salesforce Marketing Cloud 0% 64 0.08
Iterable 0% 8 0.25
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
No provider stands out: pass rates sit between 86% and 90%. computed
The State of Web Vitals · October 2026 · 203,892 crawled sites · phone field datacorewebvitals.io/state-of-cwv
4
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 1.7%
772.4s
96123ms
880.02
702.0s
501.4s
HubSpot 1.6%
772.4s
94134ms
860.04
692.0s
521.3s
Klaviyo 1.5%
882.0s
89164ms
900.03
851.5s
81701ms
ActiveCampaign 0.2%
712.7s
93146ms
860.04
612.2s
431.7s
Salesforce Marketing Cloud 0%
752.5s
63228ms
790.08
642.1s
331.5s
Marketo 0%
702.8s
94155ms
840.03
652.0s
491.3s
Braze 0%
672.7s
81190ms
910.08
432.3s
331.4s
Iterable 0%
861.7s
86179ms
710.25
861.3s
86703ms
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.
Klaviyo leads on CLS: 90% of its sites pass. ActiveCampaign trails at 86%. computed
The State of Web Vitals · October 2026 · 203,892 crawled sites · phone 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.