Usercentrics: impact on page speed
Category: Consent management
Usercentrics displays the consent banner and manages consent for other scripts. Because it must run before consent-dependent tags, it loads early on every first visit.
On 2.3 % of the 4108 homepages measured, Usercentrics is among the five heaviest third parties. Where it is, it takes a median of 77 ms of main-thread time; on the heaviest quarter of those sites it takes 184 ms or more.
2.3 %
of homepages: among the five heaviest third parties
77 ms
median main-thread time
184 ms
main-thread time on the heaviest quarter (p75)
199 KB
median transfer size
Distribution across homepages
Percentiles across 96 homepages with Usercentrics.
| Percentile | Main-thread time | Transfer size |
|---|---|---|
| p25 |
44 ms
|
162 KB |
| Median |
77 ms
|
199 KB |
| p75 |
184 ms
|
232 KB |
| p90 |
284 ms
|
265 KB |
In context
By median main-thread time, Usercentrics ranks 40th of 65 third parties in the benchmark, lighter than Hotjar and heavier than mPulse.
On 14 % of the homepages where it appears, Usercentrics alone uses 250 milliseconds of main-thread time or more, the mark from which Lighthouse flags third-party code.
Homepages with Usercentrics weigh 2.8 MB at the median (JavaScript: 1.3 MB), homepages without it 4.3 MB (JavaScript: 1.6 MB).
Often loaded together with
Share of homepages with Usercentrics where the other tool is also among the five heaviest third parties.
- Google Tag Manager 50 %
- Google/Doubleclick Ads 16 %
- Adobe Tag Manager 12 %
How to spot Usercentrics on your page
The current version loads loader.js from web.cmp.usercentrics.eu and then about a dozen modules for banner, second layer and controller from the same host; the configuration comes from the Usercentrics API. With automatic script blocking enabled, uc-block.bundle.js from privacy-proxy.usercentrics.eu is added on top. Lighthouse lists the tool as "Usercentrics CMP".
How to reduce the impact of Usercentrics
- Keep the number of configured services to those actually used on the site.
- Make sure the consent script is included only once, not both directly and through a tag manager.
- Check whether the banner becomes the Largest Contentful Paint element on mobile.
Frequently asked questions
How can I load Usercentrics with less impact?
Keep the number of configured services to those actually used on the site. Make sure the consent script is included only once, not both directly and through a tag manager.
Does Usercentrics affect Core Web Vitals?
Usercentrics affects the same metrics as other consent platforms, with emphasis on LCP and INP. The consent layer loads before tracking may start, and its interface is an application of its own that has to initialise before the banner can respond to a click on accept. When the layer covers the page on first load, it is often what Lighthouse reports as the largest element.
Method and sample: Third-Party Benchmark.