The State of Web Vitals

A/B testing impact

Performance impact by ab_testing 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 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
2.0s
Best LCP (p75)
Google Optimize
The State of Web Vitals · Q2 2026 · 189,915 sites · desktop field datacorewebvitals.io/state-of-cwv
2

The ranking sorted by LCP at p75, fastest first

# Provider LCP p75 Passing Sites
1 Google Optimize 2.0s 85.4%
19,928
2 AB Tasty 2.1s 83.5%
109
3 Kameleoon 2.1s 82.4%
112
4 Dynamic Yield 2.2s 78.0%
65
5 VWO 2.3s 81.6%
433
6 Convert 2.5s 73.8%
191
7 Optimizely 2.7s 73.2%
137
8 LaunchDarkly 3.3s 54.4%
131
The State of Web Vitals · Q2 2026 · 189,915 sites · desktop 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 85% 2.0s
Monetate 0% 26 85% 2.1s
AB Tasty 0.1% 109 84% 2.1s
Kameleoon 0.1% 112 82% 2.1s
VWO 0.2% 433 82% 2.3s
Dynamic Yield 0% 65 78% 2.2s
Convert 0.1% 191 74% 2.5s
Optimizely 0.1% 137 73% 2.7s
LaunchDarkly 0.1% 131 54% 3.3s
Split.io 0% 9 33% 3.4s
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

85% of Google Optimize sites pass LCP. LaunchDarkly trails 31 points behind, leaving 46% of its sites failing. 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
Google Optimize 10.5%
852.0s
9961ms
760.10
811.6s
581.2s
VWO 0.2%
822.3s
9896ms
780.10
771.7s
541.2s
Convert 0.1%
742.5s
99108ms
700.13
702.0s
561.5s
Optimizely 0.1%
732.7s
92122ms
700.13
751.8s
591.1s
LaunchDarkly 0.1%
543.3s
81128ms
640.29
572.6s
73815ms
Kameleoon 0.1%
822.1s
95118ms
730.12
851.6s
531.1s
AB Tasty 0.1%
842.1s
9793ms
700.13
841.5s
71870ms
Dynamic Yield 0%
782.2s
83188ms
640.13
761.5s
68985ms
Monetate 0%
852.1s
96138ms
770.08
921.6s
621.1s
Split.io 0%
333.4s
80128ms
500.33
332.6s
671.8s
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: 85% of its sites pass. LaunchDarkly trails at 54%. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · desktop 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