What's the difference between RUM and field data?
In discussions about website performance data, three terms are commonly used: Lab data, field data, and Real User Monitoring (RUM) data:
What is lab data?
Lab data is based on synthetic data, which is generated under controlled conditions such as specific internet speeds and smartphone models.
Tools like Lighthouse and WebPageTest are used to gather lab data.
What is field and RUM data?
Field data, as used by Google, is based on real users. RUM data is also based on real users. Despite these different terms, there is no real difference between these types of data. Google simply prefers to use the term field data because it is more descriptive.
Tools like RUMvision and Pagespeed Insights are used to collect data from real users.
Understanding the distinction between these different types of data can help you more accurately assess and optimize the performance of your website.
Core Web Vitals are based on field data
If you want to know if your website passes the Core Web Vitals Assessment, it is important to know that you need to look at field / RUM data. Lighthouse scores do not play a role for your Core Web Vitals.
Any website with enough pageviews has Core Web Vitals data. To see how your website scores on this data, we have created a free Core Web Vitals checker.
Conclusion
Pretty simple, lab data is not based on your real users and field and RUM data both are. Field and RUM data for that purpose also count towards your Core Web Vitals.
