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
21,139
Sites in sample
Combined across all items
2.3s
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 2.3s 77.8%
109
2 Google Optimize 2.3s 80.7%
19,960
3 VWO 2.4s 76.2%
433
4 Kameleoon 2.5s 76.7%
112
5 Dynamic Yield 2.7s 65.5%
65
6 Convert 2.7s 66.5%
192
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
Statsig 0% 2 100% 2.2s
Google Optimize 10.5% 19,960 81% 2.3s
Monetate 0% 26 78% 2.4s
AB Tasty 0.1% 109 78% 2.3s
Kameleoon 0.1% 112 77% 2.5s
VWO 0.2% 433 76% 2.4s
Optimizely 0.1% 137 68% 2.9s
Convert 0.1% 192 66% 2.7s
Dynamic Yield 0% 65 65% 2.7s
Split.io 0% 9 57% 3.6s
LaunchDarkly 0.1% 131 45% 4.1s
Evolv ai 0% 1 2.8s
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
VWO 0.2%
762.4s
74204ms
830.05
692.0s
531.3s
AB Tasty 0.1%
782.3s
76194ms
720.12
731.8s
56933ms
Statsig 0%
1002.2s
50402ms
1000.02
502.0s
100540ms
Evolv ai 0%
02.8s
0494ms
00.26
02.4s
01.7s
Google Optimize 10.5%
812.3s
94125ms
870.03
731.9s
541.3s
Convert 0.1%
662.7s
77196ms
800.07
692.1s
511.5s
Kameleoon 0.1%
772.5s
62241ms
770.07
701.9s
531.1s
Dynamic Yield 0%
652.7s
40320ms
640.22
712.0s
631.1s
LaunchDarkly 0.1%
454.1s
67254ms
710.13
453.0s
541.2s
Split.io 0%
573.6s
50295ms
430.22
432.9s
571.5s
Optimizely 0.1%
682.9s
61239ms
780.09
612.2s
441.2s
Monetate 0%
782.4s
45230ms
780.07
701.9s
391.1s
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 (16) → Chat & messaging (17) → Bot detection (8) → Chrome field data from 189,915 sites, representing millions of real page loads · How we measured