Lessons
-
Introduction
-
SEO
- Snippet's clickability in search engines
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Indexing
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Headings H1-H6
Images have the "alt" attribute.
The Title attribute of links
Content robots.txt
Duplicate "title"
Duplicate "description"
Human-understandable name of the picture
Rules for formatting text on a page
Micro-markup format requirements and recommendations
Validation microdata Google
Human-friendly link format
Errors in Robots.txt
The content of the site map
The site map file
Link formatting requirements
Hreflang tag
"canonical" tag
Spelling of interactive interface elements
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Speed
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Number of network requests
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An overabundance of small pictures
Grouping CSS files
Grouping JavaScript files
An overabundance of font files
Redirects when uploading files
Availability of end-to-end CSS, JS files
Uploading duplicate files
Using JavaScript facades
Redirecting JavaScript code
Redirect from/to www version
Using sprite technology
The video player is connected correctly
- General assessment
- Server Settings
- Showing the first content
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Size of graphic files
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Minification of the embedded JavaScript code of the page
Minification of the embedded CSS code of the page
Minification of images without loss of quality
The total size of all images on the page
Font Optimization
An overabundance of monochrome icons
The presence of a monochrome font
Data optimization:Image URLs
Animated image format MP4, WEBM, SVG instead of GIF and WEBP
Cropping monophonic fields in images
Using the WebP format in images
Too high-quality images without using compression
Suitable video bitrate
Excessively large images
- Server performance
- Blockages
- The amount of code
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Number of network requests
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Mobile adaptation
- Broken layout
- Convenience
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Software errors
- Code
- Mail operation
- Availability
- Server Settings
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Convenience
- Text readability
- Interface
- Visual defects
- Interaction with other programs
- Image Favicon
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Vulnerabilities
- Code
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Server Settings
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Uploading all page files via HTTPS
Strict-https header for increased security
Private access to service files
Encrypted IPv6 connection
Enabled error display in the north
SSL certificate validity
HTTPS Availability
Redirects to protected
Vulnerabilities of a secure SSL connection
HTTP headers for increased security
- Third-party services
An overabundance of small pictures
To download a file, the browser spends time on service operations: establishing a connection, sending a request, receiving a response, closing a connection. This time is constant and does not depend on the speed of the Internet connection. For example, with a very fast Internet connection, it will take 1 millisecond to download the contents of the file, and up to 100 for service operations. The execution time of service operations depends on the network latency — ping, and not on the speed of the Internet connection.
To speed up the site, programmers group many small icons into one large file. This is usually a CSS or HTML file. This is done using data url technology.
Here are examples of the data url of a 1-by-1 pixel PNG image.
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAC0lEQVQIW2P4DwQACfsD/Z8fLAAAAAAASUVORK5CYII=">
.element {
background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAC0lEQVQIW2P4DwQACfsD/Z8fLAAAAAAASUVORK5CYII=)
}
You can convert any file to data url. [Conversion service](https://datauri.ai /) files.
Below is an example of how the download speed changes if the icons are not uploaded as a separate file, but transferred to HTML code as a data url.
Demonstration
PHP code
HTML code
<?php
$mode = $_GET['mode'] ?? '';
$base64 = 'data:image/png;base64,'.base64_encode(file_get_contents('icon-64.png'));
?><!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
.btn {
color: #000;
display: inline-block;
margin-bottom: 5px;
text-decoration: none;
padding: 5px 10px;
border: 1px solid #000;
border-radius: 5px;
}
.btn:hover {
background-color: #ddd;
}
.btn.active {
background-color: #000;
color: #fff;
}
</style>
<script>
window.addEventListener("load", (event) => {
document.querySelector('#page-load').innerHTML = 'Страница загрузилась (событие window.onload) за <b>'+(performance.now()/1000)+'с</b>.';
});
</script>
</head>
<body style="font-family: sans-serif;">
Режим: <a class="btn <?=$mode === '' ? 'active' : ''?>" href="./icons_count.php">Иконки файлами</a> <a class="btn <?=$mode === '64' ? 'active' : ''?>" href="./icons_count.php?mode=64">Иконки base64</a>
<br />
<p>На странице 100 иконок.</p>
<p id="page-load">Тут отобразится время загрузки страницы (вызова события window.onload)</p>
<?php for($i = 0; $i < 100;++$i) { ?>
<img src="<?=$mode === '64' ? $base64 : './icon-64.png?t='.microtime(true).'.'.$i ?>" />
<?php } ?>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
.btn {
color: #000;
display: inline-block;
margin-bottom: 5px;
text-decoration: none;
padding: 5px 10px;
border: 1px solid #000;
border-radius: 5px;
}
.btn:hover {
background-color: #ddd;
}
.btn.active {
background-color: #000;
color: #fff;
}
</style>
<script>
window.addEventListener("load", (event) => {
document.querySelector('#page-load').innerHTML = 'Страница загрузилась (событие window.onload) за <b>'+(performance.now()/1000)+'с</b>.';
});
</script>
</head>
<body style="font-family: sans-serif;">
Режим: <a class="btn active" href="./icons_count.php">Иконки файлами</a> <a class="btn " href="./icons_count.php?mode=64">Иконки base64</a>
<br />
<p>На странице 100 иконок.</p>
<p id="page-load">Тут отобразится время загрузки страницы (вызова события window.onload)</p>
<img src="./icon-64.png?t=1780780080.4391.0" />
<img src="./icon-64.png?t=1780780080.4391.1" />
<img src="./icon-64.png?t=1780780080.4391.2" />
<img src="./icon-64.png?t=1780780080.4391.3" />
<img src="./icon-64.png?t=1780780080.4391.4" />
<img src="./icon-64.png?t=1780780080.4391.5" />
<img src="./icon-64.png?t=1780780080.4391.6" />
<img src="./icon-64.png?t=1780780080.4392.7" />
<img src="./icon-64.png?t=1780780080.4392.8" />
<img src="./icon-64.png?t=1780780080.4392.9" />
<img src="./icon-64.png?t=1780780080.4392.10" />
<img src="./icon-64.png?t=1780780080.4392.11" />
<img src="./icon-64.png?t=1780780080.4392.12" />
<img src="./icon-64.png?t=1780780080.4392.13" />
<img src="./icon-64.png?t=1780780080.4392.14" />
<img src="./icon-64.png?t=1780780080.4392.15" />
<img src="./icon-64.png?t=1780780080.4392.16" />
<img src="./icon-64.png?t=1780780080.4392.17" />
<img src="./icon-64.png?t=1780780080.4392.18" />
<img src="./icon-64.png?t=1780780080.4392.19" />
<img src="./icon-64.png?t=1780780080.4392.20" />
<img src="./icon-64.png?t=1780780080.4392.21" />
<img src="./icon-64.png?t=1780780080.4392.22" />
<img src="./icon-64.png?t=1780780080.4392.23" />
<img src="./icon-64.png?t=1780780080.4392.24" />
<img src="./icon-64.png?t=1780780080.4392.25" />
<img src="./icon-64.png?t=1780780080.4392.26" />
<img src="./icon-64.png?t=1780780080.4392.27" />
<img src="./icon-64.png?t=1780780080.4392.28" />
<img src="./icon-64.png?t=1780780080.4392.29" />
<img src="./icon-64.png?t=1780780080.4392.30" />
<img src="./icon-64.png?t=1780780080.4392.31" />
<img src="./icon-64.png?t=1780780080.4392.32" />
<img src="./icon-64.png?t=1780780080.4392.33" />
<img src="./icon-64.png?t=1780780080.4392.34" />
<img src="./icon-64.png?t=1780780080.4392.35" />
<img src="./icon-64.png?t=1780780080.4392.36" />
<img src="./icon-64.png?t=1780780080.4392.37" />
<img src="./icon-64.png?t=1780780080.4392.38" />
<img src="./icon-64.png?t=1780780080.4392.39" />
<img src="./icon-64.png?t=1780780080.4392.40" />
<img src="./icon-64.png?t=1780780080.4392.41" />
<img src="./icon-64.png?t=1780780080.4392.42" />
<img src="./icon-64.png?t=1780780080.4392.43" />
<img src="./icon-64.png?t=1780780080.4392.44" />
<img src="./icon-64.png?t=1780780080.4392.45" />
<img src="./icon-64.png?t=1780780080.4392.46" />
<img src="./icon-64.png?t=1780780080.4392.47" />
<img src="./icon-64.png?t=1780780080.4392.48" />
<img src="./icon-64.png?t=1780780080.4392.49" />
<img src="./icon-64.png?t=1780780080.4392.50" />
<img src="./icon-64.png?t=1780780080.4392.51" />
<img src="./icon-64.png?t=1780780080.4392.52" />
<img src="./icon-64.png?t=1780780080.4392.53" />
<img src="./icon-64.png?t=1780780080.4392.54" />
<img src="./icon-64.png?t=1780780080.4392.55" />
<img src="./icon-64.png?t=1780780080.4392.56" />
<img src="./icon-64.png?t=1780780080.4392.57" />
<img src="./icon-64.png?t=1780780080.4392.58" />
<img src="./icon-64.png?t=1780780080.4392.59" />
<img src="./icon-64.png?t=1780780080.4392.60" />
<img src="./icon-64.png?t=1780780080.4392.61" />
<img src="./icon-64.png?t=1780780080.4392.62" />
<img src="./icon-64.png?t=1780780080.4392.63" />
<img src="./icon-64.png?t=1780780080.4392.64" />
<img src="./icon-64.png?t=1780780080.4392.65" />
<img src="./icon-64.png?t=1780780080.4392.66" />
<img src="./icon-64.png?t=1780780080.4392.67" />
<img src="./icon-64.png?t=1780780080.4392.68" />
<img src="./icon-64.png?t=1780780080.4392.69" />
<img src="./icon-64.png?t=1780780080.4392.70" />
<img src="./icon-64.png?t=1780780080.4392.71" />
<img src="./icon-64.png?t=1780780080.4392.72" />
<img src="./icon-64.png?t=1780780080.4392.73" />
<img src="./icon-64.png?t=1780780080.4392.74" />
<img src="./icon-64.png?t=1780780080.4392.75" />
<img src="./icon-64.png?t=1780780080.4392.76" />
<img src="./icon-64.png?t=1780780080.4392.77" />
<img src="./icon-64.png?t=1780780080.4392.78" />
<img src="./icon-64.png?t=1780780080.4392.79" />
<img src="./icon-64.png?t=1780780080.4392.80" />
<img src="./icon-64.png?t=1780780080.4392.81" />
<img src="./icon-64.png?t=1780780080.4392.82" />
<img src="./icon-64.png?t=1780780080.4392.83" />
<img src="./icon-64.png?t=1780780080.4392.84" />
<img src="./icon-64.png?t=1780780080.4392.85" />
<img src="./icon-64.png?t=1780780080.4392.86" />
<img src="./icon-64.png?t=1780780080.4392.87" />
<img src="./icon-64.png?t=1780780080.4392.88" />
<img src="./icon-64.png?t=1780780080.4392.89" />
<img src="./icon-64.png?t=1780780080.4392.90" />
<img src="./icon-64.png?t=1780780080.4392.91" />
<img src="./icon-64.png?t=1780780080.4392.92" />
<img src="./icon-64.png?t=1780780080.4392.93" />
<img src="./icon-64.png?t=1780780080.4392.94" />
<img src="./icon-64.png?t=1780780080.4392.95" />
<img src="./icon-64.png?t=1780780080.4392.96" />
<img src="./icon-64.png?t=1780780080.4392.97" />
<img src="./icon-64.png?t=1780780080.4392.98" />
<img src="./icon-64.png?t=1780780080.4392.99" />
</body>
</html>