site-speed-optimization

site-speed-optimization is a skill for Claude Code, Codex from thisisAhsanIqbal/nextjs-seo-audit. It costs 62 tokens per session (668 once invoked), scanned A, original, MIT.

A webpage speed checker that reviews HTML, CSS, images, and some Next.js image usage for page-load issues.

In plain words
What is it for?
Use it to check stylesheet counts, inline CSS, image formats, missing alt text, and Next.js Image usage. It does not cover every speed issue, such as lazy loading or render-blocking scripts.
Why use it?
It helps find page structure and asset choices that can make a page slower, less accessible, or harder for search engines to understand.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is **Note**: Render-blocking scripts, image dimensions/lazy loading, preconnect hints, and font loading are handled by the [core-web-vitals](../core-web-vitals/SKI.

Good fit Use it to check stylesheet counts, inline CSS, image formats, missing alt text, and Next.js Image usage. It does not cover every speed issue, such as lazy loading or render-blocking scripts.

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Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/thisisAhsanIqbal/nextjs-seo-audit
agentmods
npx agentmods add skills/thisisahsaniqbal/nextjs-seo-audit/site-speed-optimization

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 site-speed-optimization

README.md
[![agentmods](https://agentmods.dev/badge/skills/thisisahsaniqbal/nextjs-seo-audit/site-speed-optimization/github.svg)](https://agentmods.dev/skills/thisisahsaniqbal/nextjs-seo-audit/site-speed-optimization)
Your own site
<a href="https://agentmods.dev/skills/thisisahsaniqbal/nextjs-seo-audit/site-speed-optimization"><img src="https://agentmods.dev/badge/skills/thisisahsaniqbal/nextjs-seo-audit/site-speed-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 site-speed-optimization

Your own site · 80×15
<a href="https://agentmods.dev/skills/thisisahsaniqbal/nextjs-seo-audit/site-speed-optimization"><img src="https://agentmods.dev/badge/skills/thisisahsaniqbal/nextjs-seo-audit/site-speed-optimization.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 62 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 668 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.
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 $0.00062 $0.00668
Opus 5 $0.00031 $0.00334
Sonnet 5 $0.00012 $0.00134
Haiku 4.5 $0.00006 $0.00067

Measured 10d ago against content hash ad474f05f46c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

site-speed-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 10d 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.

skills/site-speed-optimization/SKILL.md · 66 lines

How it starts

The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Site Speed Optimization

Audit HTML-level factors that affect page load speed.

Note: Render-blocking scripts, image dimensions/lazy loading, preconnect hints, and font loading are handled by the core-web-vitals skill. Do not duplicate those checks here.

1. Total script count

Count all <script src="..."> elements:

  • More than 10 external scripts → ⚠️ WARN "Consider bundling or removing unused scripts"
  • 10 or fewer → ✅ PASS

2. Inline CSS volume

Measure total character count of all style="..." attributes + <style> element contents:

Condition Status
Total > 5000 characters ⚠️ WARN "Move styles to external stylesheet for caching"
Total ≤ 5000 ✅ PASS

3. Stylesheet loading

  • Count <link rel="stylesheet"> elements
  • If stylesheets > 3 → ⚠️ WARN "Consider combining CSS files"

4. Image alt text

Condition Status
All images have alt attribute ✅ PASS
Any image missing alt ❌ FAIL "Critical for SEO and accessibility"

5. Image formats

  • Images with .jpg, .jpeg, .png, .gif extensions → ⚠️ WARN "Consider WebP or AVIF for smaller file sizes"

6. Next.js Image component

  • Images not using /_next/image src → ⚠️ WARN "Consider using Next.js <Image> component for automatic optimization"
  • Skip this check if the site is not a Next.js project

Edge cases

  • Inline <script> tags (no src) should be counted separately from external scripts — they contribute to page weight but not network requests
  • <style> elements inside <noscript> blocks should be excluded from inline CSS volume
  • Base64-encoded images (src="data:image/...") bypass network loading but increase HTML size — flag as ⚠️ WARN if total base64 content exceeds 10KB
  • SVG images (<img src="*.svg">) do not need WebP/AVIF conversion — exclude from image format checks
  • Next.js <Image> component detection: look for /_next/image in src or srcset attributes, or data-nimg attribute
  • Dynamically injected scripts (via JS) are not visible in static HTML — note this limitation

Read the full file on GitHub · 66 lines

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. 10d ago First seen · 66 lines · 62 tokens per session scan A ad474f05f46c

Subscribe to this mod's changes

site-speed-optimization is a skill published in the GitHub repository thisisAhsanIqbal/nextjs-seo-audit (7 stars, last pushed 6mo ago), licensed MIT. It adds 62 tokens to every session and 668 once invoked, about $0.0003 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 2026-08-31.

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