The State of Web Vitals

A/B testing impact

Performance impact by ab_testing provider.

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

At a glance the headline numbers for A/B testing impact

Performance impact by ab_testing provider.

8
Providers ranked
After min-sites filter
21,106
Sites in sample
Combined across all items
2.2s
Best LCP (p75)
AB Tasty
The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv
2

The ranking sorted by LCP at p75, fastest first

# Provider LCP p75 Passing Sites
1 AB Tasty 2.2s 77.8%
109
2 Google Optimize 2.3s 80.7%
19,928
3 VWO 2.4s 76.2%
433
4 Kameleoon 2.4s 76.7%
112
5 Dynamic Yield 2.7s 65.5%
65
6 Convert 2.7s 66.9%
191
7 Optimizely 2.9s 68.0%
137
8 LaunchDarkly 4.1s 44.8%
131
The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv
3

Passing LCP per provider which group passes the LCP most often

ProviderSitesPassing LCPp75
Google Optimize 10.5% 19,928 81% 2.3s
Monetate 0% 26 78% 2.4s
AB Tasty 0.1% 109 78% 2.2s
Kameleoon 0.1% 112 77% 2.4s
VWO 0.2% 433 76% 2.4s
Optimizely 0.1% 137 68% 2.9s
Convert 0.1% 191 67% 2.7s
Dynamic Yield 0% 65 66% 2.7s
Split.io 0% 9 57% 3.2s
LaunchDarkly 0.1% 131 45% 4.1s
Good Needs Improvement Poor Sorted best-passing first · median colored by its own rating · pass = good LCP (2.5s at p75) · one value per site

81% of Google Optimize sites pass LCP. LaunchDarkly trails 36 points behind, leaving 55% of its sites failing. 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
Google Optimize 10.5%
812.3s
94125ms
870.03
731.9s
541.3s
VWO 0.2%
762.4s
74204ms
830.05
692.0s
531.3s
Convert 0.1%
672.7s
77197ms
800.07
692.1s
511.5s
Optimizely 0.1%
682.9s
61239ms
780.09
612.2s
441.2s
LaunchDarkly 0.1%
454.1s
67254ms
710.13
453.0s
541.2s
Kameleoon 0.1%
772.4s
62242ms
770.07
701.9s
531.1s
AB Tasty 0.1%
782.2s
76194ms
720.12
731.8s
56927ms
Dynamic Yield 0%
662.7s
40322ms
640.21
711.9s
631.1s
Monetate 0%
782.4s
45232ms
780.06
701.9s
391.1s
Split.io 0%
573.2s
50283ms
430.20
432.6s
571.2s
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.

Google Optimize leads on LCP: 81% of its sites pass. LaunchDarkly trails at 45%. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv
Related signals Maps (4) → CDN (15) → Chat & messaging (17) → Bot detection (7) → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured