Lessons
-
Introduction
-
SEO
- Broken links
- Site map
- Semantic markup
- Robots.txt
- References
- Text
- Duplicates
- Basic
- Pictures
-
Speed
-
Minification
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Minification of CSS to reduce its volume
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
Minification of JavaScript files to reduce its volume
Unused CSS code
Data optimization:Image URLs
Animated image format MP4, WEBM, SVG instead of GIF and WEBP
Unused JavaScript code
Using the WebP format in images
Too high-quality images without using compression
Suitable video bitrate
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Reducing requests
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An overabundance of small pictures
Grouping CSS files
Grouping JavaScript files
An overabundance of font files
Availability of end-to-end CSS, JS files
The presence of a monochrome font
Uploading duplicate files
Using JavaScript facades
Redirecting JavaScript code
Adding lazy loading
Redirect from/to www version
- Fonts
- Loading time
- Server Settings
- Pictures
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The first content
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The sequence of connecting JavaScript files
Font display mode
Setting up a pre-connection
Removing lazy loading
Long JavaScript code execution time
File upload delayed or on demand
The server is located in the same country where the users of the site live
No requests to another country that cause page loading to be blocked
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Minification
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Mobility
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Screen support
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Adapting the layout to a Full HD computer monitor
Adapting the layout for a horizontal tablet
Adapting the layout for a horizontal phone
Screenshots for the mini-report
How blocks break the page layout
Adapting the layout to an HD computer monitor
Adapting the layout for a vertical tablet
Adapting the layout for a vertical phone
- Comfort
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Screen support
- Bugs
-
Convenience
- Social networks
- Web Application Manifest
- Favicons
- Basic
- Text readability
-
Vulnerabilities
- Encrypted connection
- Exploits
- Vulnerabilities
Acceptable size of the HTML code of the page
Opening any link in the browser, the first thing the user receives is the HTML code of the page. Its large volume is rarely justified. Large pages not only take a long time to load, but also require a lot of computing resources to display. This slows down the overall page load.
Use delayed loading. For example, in a product profile in an online store, product recommendations can be loaded after the entire page has been loaded. The user will see them in 10 seconds at the earliest when they scroll through the page. Therefore, it makes no sense to load these blocks at once.
You can also use an HTML code minifier. It will remove extra characters like extra spaces, line breaks, comments, etc. But their work can take a long time, so use them only if the code you are optimizing is cached.
Try not to exceed 120 KB of the HTML code of the page.
Comparison of browser processing time of a large and small HTML page:
Demonstration
PHP code
HTML code
<?php
$mode = $_GET['mode'] ?? '';
?><!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
.btn {
color: #000;
text-decoration: none;
padding: 5px 10px;
border: 1px solid #000;
border-radius: 5px;
}
.btn:hover {
background-color: #ddd;
}
.btn.active {
background-color: #000;
color: #fff;
}
</style>
<script>
document.addEventListener("DOMContentLoaded", (event) => {
document.querySelector('#page-load').innerHTML = 'Событие DOMContentLoaded выполнилось в <b>'+(performance.now()/1000)+'с</b>.';
});
</script>
</head>
<body style="font-family: sans-serif;">
Режим: <a class="btn <?=$mode === '' ? 'active' : ''?>" href="./over_size_page.php">Файл 1 000 DOM элементов 25 КБ</a> <a class="btn <?=$mode === 'big' ? 'active' : ''?>" href="./over_size_page.php?mode=big">Файл 20 000 DOM элементов 490 КБ</a>
<p id="page-load">Тут отобразится время вызова события DOMContentLoaded</p>
<?php for($i = 0;$i < ($mode === 'big' ? 10000 : 500); ++$i) { ?>
<div><span><?=$i?></span></div>
<?php } ?>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
.btn {
color: #000;
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>
document.addEventListener("DOMContentLoaded", (event) => {
document.querySelector('#page-load').innerHTML = 'Событие DOMContentLoaded выполнилось в <b>'+(performance.now()/1000)+'с</b>.';
});
</script>
</head>
<body style="font-family: sans-serif;">
Режим: <a class="btn active" href="./over_size_page.php">Файл 1 000 DOM элементов 25 КБ</a> <a class="btn " href="./over_size_page.php?mode=big">Файл 20 000 DOM элементов 490 КБ</a>
<p id="page-load">Тут отобразится время вызова события DOMContentLoaded</p>
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</body>
</html>