core-web-vitals

Audit HTML patterns for LCP, CLS, and INP risk factors.

7|Updated Feb 19, 2026
One-click install
npx skills add https://github.com/thisisAhsanIqbal/nextjs-seo-audit --skill core-web-vitals-thisisahsaniqbal
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: core-web-vitals
Source: https://github.com/thisisAhsanIqbal/nextjs-seo-audit/tree/main/skills/core-web-vitals
Command: npx skills add https://github.com/thisisAhsanIqbal/nextjs-seo-audit --skill core-web-vitals-thisisahsaniqbal

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Core Web Vitals problems (LCP, CLS, INP) are often caused by specific HTML and resource-loading patterns, and fixing them can be slow without a structured audit that maps issues to actionable improvements.

Core Features & Use Cases

  • LCP risk detection: Flags likely Largest Contentful Paint blockers such as missing high fetch priority, lazy-loading the LCP element, render-blocking resources, and weak preload/font-loading patterns.
  • CLS stability checks: Identifies layout-shift causes including missing image/video dimensions, unstable embeds, and font-display issues that trigger FOIT.
  • INP responsiveness analysis: Highlights main-thread blockers like synchronous scripts, inline heavy scripts, and problematic event handling patterns, plus third-party script volume risk.
  • Use case example: Review a landing page HTML that triggers PageSpeed warnings to locate the most probable LCP/CLS/INP culprits and prioritize fixes.

Quick Start

Use the core-web-vitals skill to audit the target page HTML for likely LCP, CLS, and INP risk factors and return a prioritized risk summary.

Frequently Asked Questions about core-web-vitals

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I find HTML patterns that cause Core Web Vitals issues?▼

To find HTML patterns causing Core Web Vitals issues, audit your page markup to evaluate LCP, CLS, and INP-related resource-loading behavior. This identifies likely performance blockers and maps them to actionable improvements.

What triggers poor LCP scores in my page HTML?▼

Poor LCP scores are triggered by HTML patterns like lazy-loading the LCP element, missing high fetch priority, render-blocking resources, and weak preload or font-loading patterns that delay largest contentful paint.

How do I fix layout shift warnings from PageSpeed Insights?▼

Fix layout shift warnings by checking your HTML for missing image and video dimensions, unstable embeds, and font-display issues that trigger FOIT, as these are primary CLS culprits identified during an audit.

Can an HTML audit detect main-thread blockers for INP responsiveness?▼

An HTML audit can detect INP responsiveness blockers by highlighting synchronous scripts, heavy inline scripts, problematic event handling patterns, and third-party script volume risk that block the main thread.

How do I prioritize Core Web Vitals fixes for a landing page?▼

Prioritize Core Web Vitals fixes by auditing the landing page HTML to locate the most probable LCP, CLS, and INP culprits. This returns a prioritized risk summary to guide remediation efforts.