web-performance-optimization

web-performance-optimization is a skill for Claude Code from bobmatnyc/claude-mpm-skills. It costs 29 tokens per session (1,541 once invoked), scanned A, original, MIT.

A guide to improving how quickly web pages load and respond, using browser performance measurements such as Core Web Vitals.

In plain words
What is it for?
It supports work such as optimizing images, compression, caching, code splitting, page transitions, and performance monitoring.
Why use it?
It helps find slow loading, large downloads, and other performance problems that can hurt usability and search visibility.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter.

not rated 74repo 1mo ago A scan Socket: passSnyk: passSkillSpector: pass 29 tokens original MIT

Good fit It supports work such as optimizing images, compression, caching, code splitting, page transitions, and performance monitoring.

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Install with agentmods
npx agentmods add skills/bobmatnyc/claude-mpm-skills/web-performance-optimization
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add bobmatnyc/claude-mpm-skills --skill web-performance-optimization
Clone the repo
git clone --depth 1 https://github.com/bobmatnyc/claude-mpm-skills

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for web-performance-optimization

README.md
[![agentmods](https://agentmods.dev/badge/skills/bobmatnyc/claude-mpm-skills/web-performance-optimization/github.svg)](https://agentmods.dev/skills/bobmatnyc/claude-mpm-skills/web-performance-optimization)
Your own site
<a href="https://agentmods.dev/skills/bobmatnyc/claude-mpm-skills/web-performance-optimization"><img src="https://agentmods.dev/badge/skills/bobmatnyc/claude-mpm-skills/web-performance-optimization/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for web-performance-optimization

Your own site · 80×15
<a href="https://agentmods.dev/skills/bobmatnyc/claude-mpm-skills/web-performance-optimization"><img src="https://agentmods.dev/badge/skills/bobmatnyc/claude-mpm-skills/web-performance-optimization.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 29 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,541 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 21 Apr 2026
  • Snyk pass 21 Apr 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00029 $0.01541
Opus 5 $0.00015 $0.00771
Sonnet 5 $0.00006 $0.00308
Haiku 4.5 $0.00003 $0.00154

Measured 5d ago against content hash a0a7d3676a54, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

web-performance-optimization scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

universal/web/web-performance-optimization/SKILL.md · 142 lines

How it starts

The opening of the file, as written. The whole thing — 142 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Web Performance Optimization

Optimize web performance through Core Web Vitals, modern browser APIs (View Transitions, Speculation Rules), and framework-specific techniques.

When to Use This Skill

  • Improving Lighthouse scores (target: 90+)
  • Reducing page load times (target: <2.5s LCP)
  • Optimizing Core Web Vitals for SEO rankings
  • Implementing modern performance patterns (2025)
  • Debugging performance bottlenecks
  • Setting up continuous performance monitoring

Business Impact: 1 second delay = 7% conversion loss. 0.1s improvement = 8% increase in conversions.

Start Here: Quick Wins

High-ROI optimizations by time investment:

1 Hour Quick Wins (⭐⭐⭐⭐⭐ ROI):

  • Add loading="lazy" to below-fold images (40-60% weight reduction)
  • Enable compression (gzip/brotli) (70-80% transfer size reduction)
  • Add rel="preconnect" for critical origins (100-500ms savings)

1 Day Investments (⭐⭐⭐⭐ ROI):

  • Implement code splitting (30-50% bundle reduction)
  • Optimize LCP image with fetchpriority="high" (200-400ms improvement)
  • Add basic service worker (instant repeat visits)

1 Week Comprehensive (⭐⭐⭐⭐⭐ ROI):

  • Full caching strategy (HTTP headers + service workers)
  • Bundle optimization (tree shaking, 40-60% reduction)
  • Performance monitoring (Lighthouse CI + RUM)

→ See quick-wins.md for complete implementation details

Core Web Vitals at a Glance

Metric Target Weight Key Optimization
LCP (Largest Contentful Paint) <2.5s 25% Optimize images, preload critical resources
INP (Interaction to Next Paint) <200ms 30% Reduce JavaScript, break up long tasks
CLS (Cumulative Layout Shift) <0.1 25% Reserve space, optimize fonts
TBT (Total Blocking Time) <200ms 30% Code splitting, defer non-critical JS
FCP (First Contentful Paint) <1.8s 10% Eliminate render-blocking resources

→ See core-web-vitals.md for deep dive on each metric

Read the full file on GitHub · 142 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 142 lines · 29 tokens per session scan A a0a7d3676a54

Subscribe to this mod's changes

web-performance-optimization is a skill published in the GitHub repository bobmatnyc/claude-mpm-skills (74 stars, last pushed 1mo ago), licensed MIT. It adds 29 tokens to every session and 1,541 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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