audit-speed
Deep Core Web Vitals and page speed audit. Use when the user asks about page speed, Core Web Vitals, LCP, CLS, INP, FCP, TTFB, Lighthouse scores, why a page is slow, performance optimization, or resource size analysis. For broader technical SEO issues, see diagnose-seo.
Security Assessment
About audit-speed
The audit-speed skill performs deep Core Web Vitals and page speed audits with structured root-cause analysis and optimization guidance. It is designed to help diagnose why a website or web page is slow by evaluating performance metrics such as Largest Contentful Paint (LCP), Cumulative Layout Shift (CLS), Interaction to Next Paint (INP), First Contentful Paint (FCP), and Time to First Byte (TTFB). The skill uses established performance thresholds to classify issues and guide investigation into server response times, render-blocking assets, image optimization problems, layout instability, and JavaScript execution bottlenecks. It is intended for troubleshooting performance degradation, improving Lighthouse scores, and identifying resource-loading inefficiencies.
The skill provides structured diagnostic workflows for Core Web Vitals by using root-cause trees for LCP, CLS, and INP issues. It evaluates common causes such as slow server response times, oversized or improperly loaded images, blocking CSS and JavaScript, font-loading problems, layout shifts caused by missing dimensions or injected content, and excessive main-thread work from JavaScript or third-party scripts. The skill also recommends practical optimization strategies including CDN configuration, caching improvements, responsive image delivery, preload directives, font optimization, code splitting, task scheduling, and reducing synchronous processing. It additionally guides users on gathering the required audit context, including affected pages, current Lighthouse or PageSpeed Insights scores, technology stack details, and operational constraints.
This skill is useful for frontend developers, technical SEO specialists, performance engineers, web agencies, and site owners who need to improve page speed and user experience. It is particularly valuable during performance audits, Lighthouse optimization projects, Core Web Vitals remediation efforts, and troubleshooting sessions for slow-loading pages or poor responsiveness. Teams working with CMS platforms, JavaScript frameworks, server-rendered applications, or resource-heavy websites can use the skill to prioritize and structure optimization work based on measurable performance indicators.
FAQ
What metrics does the audit-speed skill analyze?
The skill analyzes Core Web Vitals and related performance metrics including LCP, CLS, INP, FCP, and TTFB.
What information should be collected before running an audit?
The audit works best when you provide target pages, existing Lighthouse or PageSpeed Insights scores, technology stack details, and any known optimization constraints such as required third-party scripts.
Can this skill diagnose issues caused by third-party scripts?
Yes. The skill includes diagnostic guidance for identifying main-thread blocking and responsiveness problems caused by analytics scripts, chat widgets, A/B testing tools, and other third-party resources.
Does the skill provide optimization recommendations?
Yes. It provides recommendations such as image optimization, caching improvements, CDN usage, font-loading strategies, render-blocking asset reduction, code splitting, and JavaScript task optimization.
Is this skill intended for general SEO audits?
No. The skill focuses specifically on page speed and Core Web Vitals analysis. For broader technical SEO investigations, a separate SEO-focused workflow may be more appropriate.
Install audit-speed
Quick Setup:
- Copy the skill folder to
.claude/skills/ - Claude will automatically detect and use the skill
Repository
calm-north/seojuice-skills