AI SEO を無料で入手してください。


What is PageSpeed Insights?

PageSpeed Insights is a free tool that measures the metrics Google uses to analyze the speed and user experience of a webpage. The tool allows you to identify issues slowing down your site and suggests ways to improve your SEO and page speed.


The PageSpeed Insights tool is owned by Google and can be accessed at the PageSpeed Insights website. It measures various metrics, including:

  • コアウェブバイタル
  • パフォーマンス
  • Accessibility
  • Best Practices
  • SEO

Below, we will briefly address these metrics measured by the PageSpeed Insights tool.


The Core Web Vitals are the metrics Google uses to determine the speed of a webpage. The metrics measured as part of the Core Web Vitals include:

  • 最大のコンテンツフルペイント(LCP)
  • 最初の入力遅延(FID)
  • 累積レイアウトシフト(CLS)

Core Web Vitals metrics

Other notable metrics that are not part of the Core Web Vitals but are also measured include:

  • 最初のコンテンツフル ペイント (FCP)
  • Interaction to Next Paint (INP)
  • 最初のバイトまでの時間 (TTFB)

ノート: Interaction to Next Paint (INP) metric will replace the First Input Delay (FID) metric in March 2024.

Core Web Vitals notable metrics


The Performance tab gives you an overview of your site’s performance. It measures a series of metrics and uses them to calculate a performance score, as shown below.

PageSpeed Insights Performance audit

The metrics measured in the performance section include:

  • First Contentful Paint
  • Largest Contentful Paint
  • Total Blocking Time
  • Cumulative Layout Shift
  • Speed Index

PageSpeed Insights Performance metrics

The performance section also reports some audits in the Opportunities, Diagnostics, and Passed Audit sections.  

  • Opportunities: Contains some suggestions to improve your page load speed
  • Performance: Contains some information about your site’s performance
  • Passed Audits: Lists the audits already applied to your site


The Accessibility section reports the audits used to determine how accessible your site is to your users. The section will list the accessibility audits that require improvements, along with those that are already applied, those you need to review manually, and those not applicable to your site.

PageSpeed Insights Accessibility audit


Best Practices

The Best Practices section lists some web development practices you could apply to your site. This section will list some best practices that have yet to be applied to your site, along with those that have already been applied and those that do not apply to your site.

PageSpeed Insights Best Practices audit



The SEO section lists the basic SEO practices you could apply to your site. This section lists the SEO practices that are not applied, along with those you need to review manually and those that are already applied to your site.

PageSpeed Insights SEO audit

🇯🇵 日本語