Email marketing impact React sites

Performance impact by email_marketing provider.

Field data PhoneDesktopAll Scope All sites October 2026 edition · All devices field outcomes · React sites only
Metric LCP INP CLS
React Scoped to 9,570 sites out of 210,902 analyzed (frameworks) Compare with all sites →
1

At a glance the headline numbers for Email marketing impact

Performance impact by email_marketing provider.

3
Providers ranked
After min-sites filter
290
Sites in sample
Combined across all items
108ms
Best INP (p75)
Mailchimp
The State of Web Vitals · October 2026 · React sites (9,570) · all devices field datacorewebvitals.io/state-of-cwv
2

The ranking sorted by INP at p75, fastest first

# Provider INP p75 Passing Sites
1 Mailchimp 108ms 97.3%
130
2 HubSpot 120ms 96.3%
90
3 Klaviyo 128ms 96.9%
70
The State of Web Vitals · October 2026 · React sites (9,570) · all devices field datacorewebvitals.io/state-of-cwv
3

Passing INP per provider which group passes the INP most often

ProviderSitesPassing INPp75
ActiveCampaign 0.2% 15 100% 156ms
Mailchimp 1.4% 130 97% 108ms
Klaviyo 0.7% 70 97% 128ms
HubSpot 0.9% 90 96% 120ms
Salesforce Marketing Cloud 0.1% 8 25% 278ms
Good Needs Improvement Poor Sorted best-passing first · median colored by its own rating · pass = good INP (200ms at p75) · one value per site
The State of Web Vitals · October 2026 · React sites (9,570) · all devices 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 1.4%
483.2s
97108ms
810.07
432.7s
242.5s
HubSpot 0.9%
643.3s
96120ms
810.07
582.6s
422.0s
Klaviyo 0.7%
732.6s
97128ms
880.04
702.0s
431.8s
ActiveCampaign 0.2%
642.6s
100156ms
790.08
572.2s
291.9s
Salesforce Marketing Cloud 0.1%
1002.0s
25278ms
1000.09
631.8s
50932ms
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.

The State of Web Vitals · October 2026 · React sites (9,570) · all devices field datacorewebvitals.io/state-of-cwv
Related signals Font services (4) → Session recording (11) → CMS (17) → Search (6) → 210,902 crawled sites with Chrome field data, representing millions of real page loads · How we measured