Personalization impact React sites

Performance impact by personalization provider.

Field data PhoneDesktopAll Scope All sites October 2026 edition · Phone 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 Personalization impact

Performance impact by personalization provider.

2
Providers ranked
After min-sites filter
337
Sites in sample
Combined across all items
0.04
Best CLS (p75)
Elfsight
The State of Web Vitals · October 2026 · React sites (9,570) · phone field datacorewebvitals.io/state-of-cwv
2

The ranking sorted by CLS at p75, fastest first

# Provider CLS p75 Passing Sites
1 Elfsight 0.04 80.0%
56
2 Algolia Recommend 0.11 74.6%
281
The State of Web Vitals · October 2026 · React sites (9,570) · phone field datacorewebvitals.io/state-of-cwv
3

Passing CLS per provider which group passes the CLS most often

ProviderSitesPassing CLSp75
Elfsight 0.6% 56 80% 0.04
Algolia Recommend 2.9% 281 75% 0.11
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
The State of Web Vitals · October 2026 · React sites (9,570) · 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
Algolia Recommend 2.9%
692.7s
82171ms
750.11
612.1s
471.6s
Elfsight 0.6%
602.9s
78189ms
800.04
692.2s
421.4s
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) · phone field datacorewebvitals.io/state-of-cwv
Related signals JS libraries (26) → Tag managers (8) → A/B testing (12) → Chat & messaging (17) → 210,902 crawled sites with Chrome field data, representing millions of real page loads · How we measured