Email marketing impact

Performance impact by email_marketing provider.

Field data PhoneDesktopAll Scope All sites Q2 2026 edition · Desktop field outcomes
Metric LCP INP CLS
1

At a glance the headline numbers for Email marketing impact

Performance impact by email_marketing provider.

5
Providers ranked
After min-sites filter
9,766
Sites in sample
Combined across all items
0.08
Best CLS (p75)
HubSpot
The State of Web Vitals · Q2 2026 · 189,915 sites · 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 79.3%
3,075
2 Klaviyo 0.09 79.0%
2,914
3 ActiveCampaign 0.10 76.8%
438
4 Mailchimp 0.10 75.9%
3,276
5 Salesforce Marketing Cloud 0.18 46.8%
63
The State of Web Vitals · Q2 2026 · 189,915 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% 3,075 79% 0.08
Klaviyo 1.5% 2,914 79% 0.09
Braze 0% 20 79% 0.07
ActiveCampaign 0.2% 438 77% 0.10
Mailchimp 1.7% 3,276 76% 0.10
Iterable 0% 8 67% 0.26
Marketo 0% 40 65% 0.18
Salesforce Marketing Cloud 0% 63 47% 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 · Q2 2026 · 189,915 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
10064ms
760.10
761.8s
511.4s
HubSpot 1.6%
862.0s
9968ms
790.08
811.6s
611.1s
Klaviyo 1.5%
901.9s
9987ms
790.09
881.3s
80669ms
ActiveCampaign 0.2%
792.3s
9972ms
770.10
721.9s
451.6s
Salesforce Marketing Cloud 0%
762.4s
98115ms
470.18
652.0s
501.6s
Marketo 0%
782.4s
10071ms
650.18
761.8s
621.1s
Braze 0%
682.7s
95124ms
790.07
632.2s
471.4s
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.

Klaviyo leads on CLS: 79% of its sites pass. Mailchimp trails at 76%. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · desktop field datacorewebvitals.io/state-of-cwv
Related signals Font services (4) → Session recording (11) → Search (5) → Performance services (8) → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured