A/B testing impact: 8 providers ranked | The State of Web Vitals 2026

LCP INP CLS

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

Performance impact by ab_testing provider.

Providers ranked

After min-sites filter

21,139

Sites in sample

Combined across all items

0.03

Best CLS (p75)

Google Optimize

The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv

The ranking sorted by CLS at p75, fastest first

#	Provider	CLS p75	Passing	Sites
1	Google Optimize	0.03	87.1%	19,960
2	VWO	0.05	82.5%	433
3	Kameleoon	0.07	76.7%	112
4	Convert	0.07	80.4%	192
5	Optimizely	0.09	78.4%	137
6	AB Tasty	0.12	72.2%	109
7	LaunchDarkly	0.13	70.8%	131
8	Dynamic Yield	0.22	63.6%	65

The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv

Passing CLS per provider which group passes the CLS most often

ProviderSitesPassing CLSp75

Statsig 0% 2 100% 0.02

Google Optimize 10.5% 19,960 87% 0.03

VWO 0.2% 433 83% 0.05

Convert 0.1% 192 80% 0.07

Optimizely 0.1% 137 78% 0.09

Monetate 0% 26 78% 0.07

Kameleoon 0.1% 112 77% 0.07

AB Tasty 0.1% 109 72% 0.12

LaunchDarkly 0.1% 131 71% 0.13

Dynamic Yield 0% 65 64% 0.22

Split.io 0% 9 43% 0.22

Evolv ai 0% 1 0.26

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

87% of Google Optimize sites pass CLS. LaunchDarkly trails 16 points behind, leaving 29% of its sites failing. computed

The State of Web Vitals · Q2 2026 · 189,915 sites · phone field datacorewebvitals.io/state-of-cwv

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 CLS: 87% of its sites pass. LaunchDarkly trails at 71%. 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