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Martino17x
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performance

Diagnose and optimize web page speed using Lighthouse audits and Core Web Vitals budgets.

Updated Aug 13, 2026
Search Tags:#caching#lighthouse#web performance#code splitting#core web vitals#image optimization#page speed
One-click install
npx skills add https://github.com/Martino17x/Sentinel-Invest --skill performance-martino17x
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: performance
Source: https://github.com/Martino17x/Sentinel-Invest/tree/main/.agents/skills/performance
Command: npx skills add https://github.com/Martino17x/Sentinel-Invest --skill performance-martino17x

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Slow-loading websites hurt user experience and search rankings, but identifying which optimizations matter most is difficult. This Skill provides a structured audit workflow with concrete performance budgets and code-level fixes for loading speed, runtime efficiency, and resource optimization. ## Core Features & Use Cases - Performance Budgets: Enforce concrete limits for page weight, JavaScript, CSS, images, fonts, and third-party scripts aligned with Core Web Vitals targets. - Critical Rendering Path Optimization: Apply preconnect, preload, deferred CSS, and script loading strategies to reduce TTFB, LCP, and render blocking. - Runtime & Asset Optimization: Fix layout thrashing, debounce handlers, virtualize long lists, and serve responsive AVIF/WebP images with proper caching headers. - Use Case: A developer whose e-commerce site scores poorly on Lighthouse can use this Skill to identify that unoptimized hero images and render-blocking scripts are the bottlenecks, then apply the provided responsive image markup and defer patterns to bring LCP under 2.5 seconds. ## Quick Start Audit my website's performance and give me prioritized optimizations to improve my Lighthouse score and Core Web Vitals.

Frequently Asked Questions about performance

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

FAQPage Schema
How do I improve my Lighthouse performance score?▼

Improving a Lighthouse performance score starts with identifying bottlenecks against Core Web Vitals budgets, then prioritizing fixes by impact. Common wins include preloading LCP images, deferring non-critical JavaScript, inlining critical CSS, and enabling Brotli compression with edge caching.

How to optimize images for faster page load?▼

Optimize images by serving AVIF or WebP formats with responsive srcset and sizes attributes so browsers download appropriately sized files. Set fetchpriority="high" and eager loading on the LCP image, while using loading="lazy" for below-fold images.

What is a good performance budget for a website?▼

A practical performance budget keeps total page weight under 1.5 MB, compressed JavaScript under 300 KB, CSS under 100 KB, above-fold images under 500 KB, fonts under 100 KB, and third-party scripts under 200 KB. These limits target roughly 4-second loads on 3G connections.

Does deferring JavaScript improve page speed?▼

Yes, deferring JavaScript with the defer attribute or type="module" prevents parser blocking and reduces Total Blocking Time. Combine this with code splitting via dynamic imports and tree shaking to ship only the code each route actually needs.

Why is my LCP slow even with optimized images?▼

Slow LCP despite optimized images usually stems from high TTFB, render-blocking resources, or missing preload hints. Check that your server responds in under 800ms, preload the LCP image with fetchpriority="high", and eliminate render-blocking CSS and synchronous scripts.

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