perf-web-optimization

perf-web-optimization is a skill for Claude Code, Codex from tech-leads-club/agent-skills. It costs 104 tokens per session (1,142 once invoked), scanned A, original, no licence file.

A web performance guide for making sites load and respond faster by improving files, images, caching, and loading behavior.

In plain words
What is it for?
Use it to optimize bundle size, image loading, caching, lazy loading, page speed, and Lighthouse performance results.
Why use it?
It helps find and reduce causes of slow pages, oversized downloads, delayed interaction, and visible content shifting.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it to optimize bundle size, image loading, caching, lazy loading, page speed, and Lighthouse performance results.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/tech-leads-club/agent-skills/perf-web-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 tech-leads-club/agent-skills --skill perf-web-optimization
Clone the repo
git clone --depth 1 https://github.com/tech-leads-club/agent-skills

Made for: Claude Code, Codex.

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 perf-web-optimization

README.md
[![agentmods](https://agentmods.dev/badge/skills/tech-leads-club/agent-skills/perf-web-optimization/github.svg)](https://agentmods.dev/skills/tech-leads-club/agent-skills/perf-web-optimization)
Your own site
<a href="https://agentmods.dev/skills/tech-leads-club/agent-skills/perf-web-optimization"><img src="https://agentmods.dev/badge/skills/tech-leads-club/agent-skills/perf-web-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 perf-web-optimization

Your own site · 80×15
<a href="https://agentmods.dev/skills/tech-leads-club/agent-skills/perf-web-optimization"><img src="https://agentmods.dev/badge/skills/tech-leads-club/agent-skills/perf-web-optimization.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 104 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,142 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
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 3 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium MCP Rug Pull · line 76
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 79
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium MCP Rug Pull · line 82
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
How audits are shown
Origin unknown 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 $0.00104 $0.01142
Opus 5 $0.00052 $0.00571
Sonnet 5 $0.00021 $0.00228
Haiku 4.5 $0.00010 $0.00114

Measured 6d ago against content hash 77471fc68e5b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

perf-web-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 6d 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.

packages/skills-catalog/skills/(performance)/perf-web-optimization/SKILL.md · 164 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Files

What ships with it

3 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. 6d ago First seen · 164 lines · 104 tokens per session scan A 77471fc68e5b

Subscribe to this mod's changes

perf-web-optimization is a skill published in the GitHub repository tech-leads-club/agent-skills (5,156 stars, last pushed yesterday), with no licence file. It adds 104 tokens to every session and 1,142 once invoked, about $0.0005 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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