HTML

analytics.html

<!-- Google Analytics -->
<script async>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0], j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= 'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f); })(window,document,'script','dataLayer','GTM-XXXXXX');
<!--<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-XXXXXX" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>-->

<!-- Yandex Metrica -->
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<!--<noscript><img src="https://mc.yandex.ru/watch/XXXXXX" style="position:absolute; left:-9999px;" alt=""></noscript>--> 

favicons.html

<link rel="icon" href="/img/favicons/favicon.ico" sizes="any">
<link rel="icon" href="/img/favicons/icon.svg" type="image/svg+xml">
<link rel="apple-touch-icon" href="/img/favicons/apple-touch-icon.png">
<link rel="manifest" href="/manifest.json">

{
  "name": "Название сайта",
  "short_name": "Название сайта",
  "description": "Описание сайта",
  "lang": "ru",
  "dir": "ltr",
  "start_url": "/",
  "scope": "/",
  "display": "minimal-ui",
  "orientation": "any",
  "theme_color": "#000000",
  "background_color": "#000000",
  "prefer_related_applications": false,
  "icons": [
    {
      "src": "/img/favicons/icon-192.png",
      "type": "image/png",
      "sizes": "192x192"
    },
    {
      "src": "/img/favicons/icon-512.png",
      "type": "image/png",
      "sizes": "512x512"
    },
    {
      "src": "/assets/img/favicons/icon.svg",
      "sizes": "any",
      "type": "image/svg",
      "purpose": "maskable"
    }
  ]
}

og.html

<link rel="canonical" href="http://localhost:3000">
<meta name="application-name" content="Главная страница — Название сайта">
<meta name="apple-mobile-web-app-title" content="Главная страница — Название сайта">
<meta property="og:title" content="Главная страница — Название сайта">
<meta property="og:locale" content="ru">
<meta property="og:description" content="Описание главной страницы">
<meta property="og:url" content="http://localhost:3000">
<meta property="og:site_name" content="Описание главной страницы">
<meta property="og:type" content="website">
<meta property="og:image" content="http://localhost:3000/img/cover.jpg">
<meta property="twitter:card" content="summary">
<meta property="twitter:title" content="Главная страница — Название сайта">
<meta property="twitter:image" content="http://localhost:3000/img/cover.jpg">

<script type="application/ld+json">
    {
        "@context": "https://schema.org",
        "@type": "WebSite",
        "headline": "Главная страница — Название сайта",
        "description": "Описание главной страницы",
        "name": "Описание главной страницы",
        "url": "http://localhost:3000"
    }
</script>

<script type="application/ld+json">
    {
        "@context": "https://schema.org",
        "@type": "BlogPosting",
        "dateModified": "2023-12-31T00:00:00+06:00",
        "datePublished": "2023-12-31T00:00:00+06:00",
        "headline": "Страница — Название сайта",
        "description": "Описание страницы",
        "name": "Описание страницы",
        "url": "http://localhost:3000"
    }
</script>

other.html

<time class="date" datetime="2023-12-31 00:00">31.12.2023</time>

picture.html

<picture>
  <!--  Desktop  -->
  <source type="image/webp" media="(min-width: 1170px)" srcset="img/image-desktop@1x.webp 1x, img/image-desktop@2x.webp 2x">
  <source media="(min-width: 1170px)" srcset="img/image-desktop@1x.jpg 1x, img/image-desktop@2x.jpg 2x">
  
  <!--  Tablet  -->
  <source type="image/webp" media="(min-width: 768px)" srcset="img/image-tablet@1x.webp 1x, img/image-tablet@2x.webp 2x">
  <source media="(min-width: 768px)" srcset="img/image-tablet@1x.jpg 1x, img/image-tablet@2x.jpg 2x">
  
  <!--  Mobile  -->
  <source type="image/webp" srcset="/img/image-mobile@1x.webp 1x, /img/image-mobile@2x.webp 2x">
  <img src="/img/image-mobile@1x.jpg" srcset="/img/image-mobile@2x.jpg 2x" width="425" height="901" alt="Картинка" loading="lazy">
</picture>

preload.html

<style><!-- Критические стили --></style>

<link rel="preload" as="style" href="/css/normalize.css?v=0.0.1" onload="this.rel='stylesheet'">
<link rel="preload" as="style" href="/css/style.css?v=0.0.1" onload="this.rel='stylesheet'">

<noscript>
    <link rel="stylesheet" href="/css/normalize.css?v=0.0.1">
    <link rel="stylesheet" href="/css/style.css?v=0.0.1">
</noscript>

<link rel="preload" as="font" href="/fonts/roboto/roboto-regular.woff2" type="font/woff2" crossorigin="anonymous">

svg-sprites.html

<div hidden>
  <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <symbol id="icon-user" viewBox="0 0 24 24" fill="none">
      <path d="M17.2166 19.3323C15.9349 17.9008 14.0727 17 12 17C9.92734 17 8.06492 17.9008 6.7832 19.3323M12 21C7.02944 21 3 16.9706 3 12C3 7.02944 7.02944 3 12 3C16.9706 3 21 7.02944 21 12C21 16.9706 16.9706 21 12 21ZM12 14C10.3431 14 9 12.6569 9 11C9 9.34315 10.3431 8 12 8C13.6569 8 15 9.34315 15 11C15 12.6569 13.6569 14 12 14Z" stroke="#000000" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"/>
    </symbol>
  </svg>
</div>

<svg width="50" height="50" aria-hidden="true"><use href="#icon-user"></use></svg>