Google’s Core Web Vitals are soon to be a search ranking factor. Google has confirmed that no index pages are considered when analysing the Core Web Vitals of a site. Pages are usually listed as ‘no index’ for a reason, so it’s obviously a cause of concern for site owners.
To analyse a website, Google grabs a group of pages to analyse and this data is then representative of the whole site. Unfortunately this strategy doesn’t consider the status of pages, such as no index. Some site owners have deliberately excluded slow pages from Search to improve their SEO rankings. However the new Google Core Web Vitals would now include these, and slow page speeds would drop scores.
Google includes no index pages because these are still accessible to site users. Core Web Vitals measure the whole page experience, so all accessible pages need to be evaluated. There is currently no way to exclude specific pages from the Core Web Vitals evaluation.