1
At a glance the headline numbers for Email marketing impact
Performance impact by email_marketing provider.
5
Providers ranked
After min-sites filter
9,785
Sites in sample
Combined across all items
0.02
Best CLS (p75)
Mailchimp
The State of Web Vitals · Q2 2026 · 189,915 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% | 3,286 | |
| 2 | Klaviyo | 0.03 | 89.7% | 2,917 | |
| 3 | ActiveCampaign | 0.04 | 85.0% | 441 | |
| 4 | HubSpot | 0.04 | 85.6% | 3,078 | |
| 5 | Salesforce Marketing Cloud | 0.09 | 79.0% | 63 |
The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv
3
Passing CLS per provider which group passes the CLS most often
ProviderSitesPassing CLSp75
Klaviyo 1.5% 2,917 0.03
Braze 0% 20 0.08
Mailchimp 1.7% 3,286 0.02
HubSpot 1.6% 3,078 0.04
ActiveCampaign 0.2% 441 0.04
Marketo 0% 40 0.03
Salesforce Marketing Cloud 0% 63 0.09
Iterable 0% 8 0.45
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
90% of Klaviyo sites pass CLS. ActiveCampaign trails 5 points behind. computed
The State of Web Vitals · Q2 2026 · 189,915 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
HubSpot 1.6%
772.4s
94134ms
860.04
692.0s
521.3s
Salesforce Marketing Cloud 0%
742.5s
64220ms
790.09
632.1s
341.5s
Braze 0%
672.7s
83190ms
890.08
442.3s
331.4s
Marketo 0%
722.6s
94156ms
830.03
642.0s
501.3s
Iterable 0%
861.9s
86185ms
710.45
861.4s
86789ms
Klaviyo 1.5%
872.0s
89163ms
900.03
851.5s
80711ms
Mailchimp 1.7%
772.4s
96123ms
880.02
702.0s
491.4s
ActiveCampaign 0.2%
692.7s
93148ms
850.04
602.3s
431.7s
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 85%. computed
The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv
Related signals Font services (4) → Session recording (11) → CMS (17) → Search (6) → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured
Chrome field data from 189,915 sites, representing millions of real page loads. How we measured.