1
At a glance the headline numbers for Email marketing impact
Performance impact by email_marketing provider.
5
Providers ranked
After min-sites filter
10,979
Sites in sample
Combined across all items
0.08
Best CLS (p75)
Klaviyo
The State of Web Vitals · October 2026 · 212,308 crawled sites · desktop field datacorewebvitals.io/state-of-cwv
2
The ranking sorted by CLS at p75, fastest first
| # | Provider | CLS p75 | Passing | Sites | |
|---|---|---|---|---|---|
| 1 | Klaviyo | 0.08 | 79.1% | 3,301 | |
| 2 | HubSpot | 0.09 | 79.1% | 3,465 | |
| 3 | ActiveCampaign | 0.10 | 76.7% | 490 | |
| 4 | Mailchimp | 0.10 | 76.0% | 3,658 | |
| 5 | Salesforce Marketing Cloud | 0.18 | 46.9% | 65 |
The State of Web Vitals · October 2026 · 212,308 crawled sites · desktop field datacorewebvitals.io/state-of-cwv
3
Passing CLS per provider which group passes the CLS most often
ProviderSitesPassing CLSp75
HubSpot 1.6% 3,465 0.09
Klaviyo 1.6% 3,301 0.08
ActiveCampaign 0.2% 490 0.10
Braze 0% 25 0.07
Mailchimp 1.7% 3,658 0.10
Iterable 0% 8 0.26
Marketo 0% 43 0.18
Salesforce Marketing Cloud 0% 65 0.18
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 76% and 79%. computed
The State of Web Vitals · October 2026 · 212,308 crawled sites · desktop 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%
802.3s
10065ms
760.10
751.8s
511.4s
HubSpot 1.6%
862.1s
9968ms
790.09
811.6s
601.2s
Klaviyo 1.6%
901.9s
9988ms
790.08
881.3s
80665ms
ActiveCampaign 0.2%
802.3s
9973ms
770.10
731.9s
461.5s
Salesforce Marketing Cloud 0%
772.4s
98114ms
470.18
662.0s
521.6s
Marketo 0%
792.4s
10076ms
630.18
761.8s
631.1s
Braze 0%
712.7s
95121ms
760.07
672.1s
521.4s
Iterable 0%
831.8s
83112ms
670.26
83970ms
83557ms
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: 79% of its sites pass. Mailchimp trails at 76%. computed
The State of Web Vitals · October 2026 · 212,308 crawled sites · desktop field datacorewebvitals.io/state-of-cwv
Related signals Font services (4) → Session recording (11) → CMS (17) → Search (6) → 212,308 crawled sites with Chrome field data, representing millions of real page loads · How we measured
212,308 crawled sites with Chrome field data, representing millions of real page loads. How we measured.