Mobile Website Speed Test
How fast your website loads on a desktop says little about how it feels on a phone. This mobile website speed test measures your pages with a mobile Lighthouse profile and shows the field data of real mobile visitors next to it, together with the causes of slow pages.
Mobile lab test: slower device, stricter results
The mobile lab test simulates a mid-range phone on a throttled connection. CPU and network are much slower than on a desktop, so heavy scripts and large images stand out here. Google mostly evaluates pages from the perspective of mobile users for ranking.
Mobile speed test results per page
For each page the test shows the mobile Lighthouse score, the Core Web Vitals from the lab and the field, page weight by resource type and the largest third parties. Every recommendation links to a guide with the specific fix.
Mobile results in context
Across 4,079 measured home pages the median mobile Lighthouse score is 42, and 64% score below 50. The median home page transfers 4.3 MB. All figures are in the website speed statistics.
FAQ
How do I test my website speed on mobile?
Enter the address above. PerfDelta tests the home page and further pages from your sitemap with a mobile profile and shows the field data of real smartphone users next to it.
Why is my mobile score lower than my desktop score?
The mobile test assumes a slower CPU and a slower network. JavaScript that barely registers on a desktop blocks the main thread on a phone for much longer.
What is a good mobile score?
Lighthouse rates 90 and above as good and below 50 as poor. Rankings rely on the Core Web Vitals of real users, though, and many pages pass those with a middling score.
How do your competitors compare? The Core Web Vitals Benchmark puts up to five websites side by side using real-user data.
Guides for every metric and finding are in the Website Speed Optimization.
PerfDelta is built by Christian Schreiber, who has been working on SEO and web performance for more than 15 years.
A free account saves your tests and shows how your values change from one test to the next. Daily monitoring with field data and alerts starts with the Solo plan.