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virahitvin8
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performance-profiling

Diagnose web performance issues using Lighthouse audits, bundle analysis, and Core Web Vitals measurement.

2|Updated May 30, 2026
Search Tags:#performance#optimization#profiling#lighthouse#bundle analysis#web performance#core web vitals
One-click install
npx skills add https://github.com/virahitvin8/crafty-gis --skill performance-profiling-virahitvin8
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: performance-profiling
Source: https://github.com/virahitvin8/crafty-gis/tree/main/GIT_STAR/.agent/skills/performance-profiling
Command: npx skills add https://github.com/virahitvin8/crafty-gis --skill performance-profiling-virahitvin8

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires lighthouse, and includes scripts (resource) components.

What problem does it solve? Web applications often suffer from slow load times, janky interactions, and bloated bundles, but developers lack a structured method to find and fix the real bottlenecks instead of guessing. ## Core Features & Use Cases - Automated Lighthouse Audits: Run the included Python script against any URL to get performance, accessibility, best-practices, and SEO scores as JSON. - Core Web Vitals Guidance: Reference targets for LCP, INP, and CLS with a 4-step profiling workflow (baseline, identify, fix, validate). - Bundle and Runtime Analysis: Tables mapping symptoms like long tasks, growing heaps, and large dependencies to concrete optimization actions. - Use Case: A developer notices a page loads slowly, runs the Lighthouse audit script to get a baseline score, then follows the bottleneck tables to code-split routes and lazy-load images. ## Quick Start Run a Lighthouse performance audit on https://example.com and tell me which Core Web Vitals need improvement.

Frequently Asked Questions about performance-profiling

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

FAQPage Schema
How do I run a Lighthouse performance audit from the command line?▼

Install the Lighthouse CLI with npm install -g lighthouse, then run the included script with python lighthouse_audit.py followed by the target URL. It returns JSON with performance, accessibility, best-practices, and SEO scores.

What are good Core Web Vitals thresholds for LCP, INP, and CLS?▼

LCP should be under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1 to be rated good. Values above 4.0 seconds, 500 milliseconds, and 0.25 respectively are considered poor.

Which tool should I use for bundle size versus runtime profiling?▼

Use a bundle analyzer for bundle size issues and Chrome DevTools Performance tab for runtime problems like long tasks over 50 milliseconds. Use the Memory tab for growing heaps and the Network tab for loading issues.

Why does the Lighthouse audit script fail to run?▼

The script fails if the Lighthouse CLI is not installed, returning an error telling you to run npm install -g lighthouse. It also times out after 120 seconds if the target page is unreachable or extremely slow.

What are the highest-impact performance optimizations to try first?▼

Enable compression, lazy-load images, and code-split routes first, as these have high impact. Caching static assets and optimizing images are medium-priority follow-ups.

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