Check Core Web Vitals Once and Fix What Matters
What Are Core Web Vitals
Core Web Vitals are three Google ranking signals measured from real users visiting your site. LCP measures how long the largest visible element takes to load — it must be under 2.5 seconds. CLS measures unexpected layout movement — it must be under 0.1. INP measures how quickly your page responds to user interactions — it must be under 200ms. These are the three thresholds to measure against when you check Core Web Vitals.
Pages that fail these thresholds are actively penalised in rankings. Fixing Core Web Vitals failures is one of the most direct ranking improvements available.
What Our Core Web Vitals Checker Does
Our pay-as-you-go Core Web Vitals checker pulls real field data from the Google PageSpeed Insights API — the same data Google uses for ranking decisions. It scores your LCP, CLS and INP against Google thresholds for both mobile and desktop, identifies the exact cause of each failure and provides prioritised fix instructions.
For LCP it identifies render-blocking scripts and slow server responses. For CLS it finds images missing explicit width and height attributes. For INP it detects slow JavaScript blocking user interactions.
Core Web Vitals and PageSpeed Are Not the Same Thing
Core Web Vitals uses real field data from actual users. PageSpeed uses lab data from a controlled environment. You need both. Run our pay-as-you-go PageSpeed analyser alongside the Core Web Vitals checker for the complete picture. Read our guide on fixing your PageSpeed score without an agency to understand the right order to tackle performance issues.
Why You Do Not Need to Check Core Web Vitals Daily
Core Web Vitals field data updates on a 28-day rolling average. Run our checker after you make site changes, after fixing identified issues, or once a month as part of regular SEO maintenance. That is all you need.
How Much Does It Cost
Core Web Vitals checker runs are pay-as-you-go: you pay per run, with no monthly fee. Run it on your five most important pages. Learn how SEO credits work at AIWebPageSEO before you top up.
Get Started
Top up SEO credits and run the pay-as-you-go Core Web Vitals checker on your most important pages today. Credits never expire.
Frequently asked questions
What are the Core Web Vitals thresholds?
Core Web Vitals are three Google ranking signals measured from real users visiting your site. LCP measures how long the largest visible element takes to load and must be under 2.5 seconds. CLS measures unexpected layout movement and must be under 0.1. INP measures how quickly the page responds to user interactions and must be under 200ms. Pages that fail these thresholds are penalised in rankings, so fixing Core Web Vitals failures is one of the most direct ranking improvements available to any site owner.
What is the difference between Core Web Vitals and PageSpeed?
Core Web Vitals use real field data collected from actual users visiting your site, while PageSpeed uses lab data gathered in a controlled environment. You need both for a complete picture of performance. Google uses field data for ranking decisions, and a Core Web Vitals checker can pull that same field data from the Google PageSpeed Insights API. Running a PageSpeed analyser alongside it shows lab-based issues, helping you decide the right order to tackle performance problems on your most important pages.
What causes LCP, CLS and INP failures?
Each metric tends to fail for different reasons. Poor LCP is often caused by render-blocking scripts and slow server responses. CLS failures commonly come from images missing explicit width and height attributes, which lets content jump around as the page loads. INP problems are usually caused by slow JavaScript blocking user interactions. When you check Core Web Vitals with a dedicated checker, it scores all three against Google thresholds for both mobile and desktop, identifies the exact cause of each failure and provides prioritised fix instructions, so you can concentrate on the issues that matter.