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 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
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Convenience
- Social networks
- Web Application Manifest
- Favicons
- Basic
- Text readability
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Security
- Encrypted connection
- Exploits
- Vulnerabilities
Using sprite technology
A sprite is a large image consisting of dozens of small ones. A sprite is created by placing all the icons on one picture, similar to sticking stickers on a blackboard. This was done in order to reduce the number of requests to the server and speed up page loading. 30 images of 2 kilobytes are loaded many times slower than one image per 60 kilobytes.
The sprite is used as follows: the background of the HTML element indicates a sprite image, and then this background is shifted so that only a certain icon is visible in the picture.
But this technology has a number of drawbacks:
- To optimize a sprite for different devices, you need to write additional CSS code. When using the data url, you specify only the background and the filling style “background-size: contain;”. When using a sprite, specify the background, the size of the element (it must be strictly specified), the scale as a percentage (for example, “background-size: 50%;”, background positioning “background-position”.
- Difficult to support. Positioning a sprite as a background requires the programmer to be more careful. And if the size of the element changes in the layout, you will need to edit the sprite itself, which is used in dozens of places on the site, and re-debug the appearance of the element. If, due to a programmer error, the size of the element changes by 1px, the element will not be displayed correctly. When using dataURL, a small smudge will not affect the appearance.
- Sprites are not verifiable by our service. And this means that you will have to check everything manually.
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