Lessons
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Introduction
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Search engine optimization
- Broken links
- Site map
- Micro-markup
- Robots.txt
- References
- Text
- Duplicates
- Basic
- Pictures
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Speed
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Minification
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Minification of CSS to reduce its volume
Minification of JavaScript files
Minification of inline CSS code
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 and WEBM 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
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Loading time
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Acceptable size of the HTML code of the page
HTML code generation time
The total volume of all images on the page
Total loading time
Total page load time.
Display time of the first graphic
Optimal time to download files from the server
Time to download files from the server under load
Blocking files
- 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
Requests to another country that cause page loading to be blocked
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Minification
- Mobility
- Bugs
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Convenience
- Social networks
- Web Application Manifest
- Favicons
- Basic
- Text readability
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Security
- Encrypted connection
- Exploits
- Vulnerabilities
Requests to another country that cause page loading to be blocked
The further away the servers are from the user, the more time it will take for the light to travel the distance back and forth. This delay is called ping and depends on the distance, the number of hops (the number of routers between the user and the site), as well as the route of network packets.
Blocking files are files that the page won’t issue the loaded event without loading. And this is a key event in the stages of page loading. Without it triggering, the page will simply freeze. That is, if the blocking file cannot load, then the browser will wait up to 30 seconds, waiting for it to load.
If you use foreign services such as counters, card APIs, authorization systems, payment systems, CDN services, captchas, etc., then make sure that the connection of these scripts is non-blocking. Otherwise, all, part or individual users will get a broken page due to network problems or the availability of foreign services.
Enable the JavaScript function in the ready event.
An example in jQuery:
$(document).ready(function () {
var script = document.createElement("script"); //
script.src = "https://example.com/script.js"; // path to your file
document.head.appendChild(script);
});
Example in native JavaScript: “javascript window.addEventListener(‘load’, function() { var script = document.createElement(“script”); // script.src = “https://example.com/script.js”; // path to your file document.head.appendChild(script); }); “`