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How To Fix A Failed Core Web Vitals Assessment

· 4 min read

Google's Core Web Vitals assessment tells you how well your website does on several user experience and page speed metrics. Passing the assessment delivers a better experience for visitors on your website and can help you rank higher in Google.

This article explains how to run a Core Web Vitals assessment, what it means if your site fails the assessment, and what you can do about it.

How to get a Core Web Vitals assessment for your website

Google's PageSpeed Insights tool offers a Core Web Vitals assessment based on real user data.

Simply enter your website URL to assess its performance:

PageSpeed Insights landing page

If your website does not meet the Core Web Vitals you will see a "Core Web Vitals Assessment: Failed" under the "Discover what your real users are experiencing" heading.

PageSpeed Insights Core Web Vitals assessment failed

To pass the assessment, at least 75% of user experiences need a "Good" rating across all three Core Web Vitals metrics.

Core Web Vitals rating thresholds

What it means if you site fails the Core Web Vitals assessment

If your site fails the Core Web Vitals assessment that means visitors are having a poor user experience on your website. For example:

The Core Web Vitals are a ranking signal, which means that your site may rank lower in Google if it doesn't pass the Core Web Vitals assessment.

Core Web Vitals assessment liable to change

In some cases you may see a message like this:

This assessment is liable to change when INP replaces FID as a Core Web Vital in March 2024.

That means that your website passes the assessment for the First Input Delay metric but doesn't pass the assessment for the newer Interaction to Next Paint metric. Interaction to Next Paint replaces First Input Delay in March 2024, so even though you pass the Core Web Vitals assessment now this will change in the future.

Core Web Vitals assessment that's liable to change

How to fix a failed Core Web Vitals assessment

Here's a step by step guide on how to approach a failed Core Web Vitals assessment:

Check for which metrics less than 75% of visitors are having a "Good" experience rating. Once you know which metrics are causing you to fail your assessment you can find metric-specific advice for optimization.

You can also run a more detailed Core Web Vitals test to see a 25-week trend of your website performance.

Core Web Vitals trend data

This way you can see whether the problem is the result of a recent regression, in which case you can point your development team toward recent changes.

Or you might see that your Core Web Vitals scores are already improving. That could be because some of your recent optimizations are already working. The Core Web Vitals data takes 28 days to fully update.

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Look for detailed insight for your Core Web Vitals data

Most page speed testing tools online will automatically give you recommendations to improve your Core Web Vitals scores.

However, this can be difficult with metrics that rely on user behavior, like Interaction to Next Paint or Cumulative Layout shift. Here using a real user monitoring tool can be helpful.

For example, DebugBear real user monitoring can provide additional data on what's causing slow interactions:

  • What page elements are users interacting with?
  • Which page elements cause the slowest interactions?
  • Are rendering delays caused by background activity on the page or by the interaction itself?

DebugBear Interaction to Next Paint breakdown

Using your own monitoring tool also means you don't have to wait 28 days to see whether your scores have improved as new data will start coming in immediately after a change has been deployed.

Continuously monitor your Core Web Vitals data

To stay on top of the Core Web Vitals assessment you need to regularly test your website and get alerted when there's a regression.

DebugBear offers page speed monitoring that combines lab-based testing, Google CrUX data, and custom real user monitoring data.

Monitor Page Speed & Core Web Vitals

DebugBear monitoring includes:

  • In-depth Page Speed Reports
  • Automated Recommendations
  • Real User Analytics Data

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