The Core Web Vitals report provides great information but, if you've ever tried to fix a Core Web Vital issue, you'll no doubt have been left somewhat disappointed and frustrated to learn that you have to wait roughly 28 days before you can validate that your site improvements have fixed an issue.
The reason for this is that the data is based on the last 28-days of data in Chrome User Experience Report (CrUX). Within this CrUX data, it's only the 75th percentile that is used which helps to remove anomolies such as network issues. Out of this reduced data set, it is not the average that is calculated but instead the worst value for each Core Web Vital. Therefore, you have to go past this 28 day window before your worst score (before your site fix) drops out of consideration in the report.
Our dashboard allows you to select the range of dates you wish to be considered for your Core Web Vitals scores. Like the Google Search Console, we use the 75th percentile and we display the worst score for each vital across the selected dates. However, we additionally give a break down of the 75th percentile worst score per day so you get more immediate feedback that the improvements you have made to your site have worked.
CrUX data is based on Chrome only and whilst many of the Core Web Vitals only work with Chromium based browsers, illuminatr can collect additional data eg. from Microsoft Edge. The Chrome browser version your users hve installed can give different results in CrUX as bug fixes are gradually rolled out with different versions. With illuminatr we have a consistent script to collect the Core Web Vitals. CrUX data also only comes from users that have opted-in to syncing their browsing history, have not set up a Sync passphrase, and have usage statistic reporting enabled.
Data for your sites pages can drop in and out of CrUX reporting depending on whether that page meets a threshold number of page views. This can be rather frustrating if you are tracking the performance of an important page and then you suddenly lose insight into the data for a month, two months, etc until the page traffic increases again. With illuminatr you don't have this problem and you can rely on page data being available as long as you at least have at least some traffic to the page.
You will have access to unlimited historical data that has been collected by illuminatr to understand how the user experience of your site has changed over time.
You can, and this is certainly useful but there are limitations. You only have a single snapshot in time of the performance of a single page so you need to run the test multiple times to at least get a representative average. The test also only provides data for the experience on a single mobile and desktop device with a consistent network connection. This is not representative of your real users who can visit your site using any number of devices and a wide range of network connection speeds. illuminatr can give you this insight to help you optimise for the people that are actually visiting your site.
There are other ways to explore the CrUX data such with the Chrome UX Report API, an interactive CrUX API explorer, or using the Chrome UX Report on BigQuery. However, your time is precious and illuminatr allows you to simply insert a single, lightweight script on your site and we handle presenting the data to you in a beautiful dashboard. That way you can focus on providing the best user experience on your site.