George S. SEO Expert

What affects website loading speed: SEO and hosting experts answers

Last year Google's new rules for evaluating online resources, Core Web Vitals, came into effect. That is, when ranking sites, Google takes into account a group of new factors:

- time to render the largest element on the page (Largest Contentful Paint);

- page interactivity (First Input Delay);

- page stability (Cumulative Layout Shift).

With Core Web Vitals factors, the search engine will especially appreciate the speed of the site and its usability. How to make the site fly and rank well?

Websites and hosting types, and how to understand that it is time to switch to a more expensive tariff?

There are four main types of hosting:

- virtual hosting;

- cloudy;

- VPS;

- dedicated servers.

With shared hosting, you share one server with other clients. You get a limited amount of resources and limited ability to make changes on the server, because your account should not interfere with your neighbors. But here everything is already set up to launch the website and such hosting is suitable even for beginners who are doing it for the first time.

Cloud hosting is similar to virtual hosting: you also share one server with other clients, however resources are limited, and hosting is provided on a turnkey basis. The difference is that here your data is duplicated simultaneously on several media. And if one of the servers fails, the site will continue to work from the other. This type of hosting is suitable for sites that need to be online without interruption 24/7.

VPS is a virtual private server. It simulates the operation of a separate physical server. There are far fewer clients on VPS hosting media, and there is less influence from neighbors on your account. In addition, you will have superuser rights with which you can configure almost any software on the server. This type of hosting is suitable for large projects with experienced developers and for sites that require finer software debugging.

A dedicated server is a separate physical machine for your personal use. Such servers are usually chosen for highly loaded projects.

Determining that it's time to switch to another tariff or another type of hosting can be difficult. Website owners usually think about this when there are not enough hosting resources: the use of RAM or processor goes off scale. In such a situation, first of all, you need to make sure that the site is well optimized, because RAM or CPU can consume unnecessary plugins or unnecessary database queries. You can check website optimization using online resources such as Google PageSpeed.

If you have already done everything possible to optimize the site, but hosting resources are still at the limit, then you can try switching to a more spacious tariff.

What is the difference in site loading speed depending on the type of server disk: HDD vs SSD vs NVMe?

An SSD is a faster alternative to a mechanical HDD. Websites on SSDs run faster than on HDDs. On SSD drives, static content is loaded more quickly. Also, dynamic content is read faster: PHP files are processed, temporary files are created and filled.

NVMe drives, on the other hand, should read information even faster than regular SSDs. The same SSD drives are present there, but they are connected via a different data transfer interface - via the PCI-E bus. And traditional SSD drives are connected through more traditional interfaces like SAS and SATA, which were originally designed for slower HDD drives.

That is, an SSD has an advantage over an HDD, and an NVMe SSD has an advantage over a regular SSD. This is a faster read and write speed and, as a result, the ability to handle heavier workloads.

What is CDN and how does it affect the speed of the website?

CDN is a network of caching servers located in different geographic locations. It is needed to reduce the content transfer time - the site will be opened from the server closest to the user.

Is it worth displaying pictures and videos on a separate server?

If images are part of the site, displaying them on a separate server is worth it when they take up an unreasonably large amount of space. Otherwise, when you open your site, your site will request images from a third-party resource, which will increase the total number of requests, and the page will load more slowly. If you still need to move the images to a separate server, use the Varnish caching proxy server on it to load media files directly from RAM.

In summary, when it comes to a medium-sized online store with a small number of images, it is better to store them locally. In the case of video, in almost 100% of situations it is better to allocate separate capacities for them.

What are the advantages of the HTTP / 2 protocol?

HTTP is a protocol that describes the rules for transmitting data on the Internet. According to these rules, the browser loads web pages, and the server receives the information that the user entered.

HTTP/1.1 is an improved version of the protocol that appeared back in 1999 and has been the standard for many years. In 2015, engineers developed the HTTP/2 protocol to replace HTTP/1.1.

The HTTP/2 protocol is built on a binary rather than a text format and is therefore faster. The updated protocol can send and receive more information in each communication cycle between the client and the server. Another plus is header compression and an improved file download prioritization algorithm: more important files will be downloaded first.

If you want to switch to HTTP/2 protocol, ask your hosting provider if the server supports HTTP/2 and install an SSL certificate for the website.

The cons are that the protocol is suitable for sites with SSL, but if the website doesn’t have SSL the speed will be lower. Also HTTP/2 requires more memory than HTTP/1.1. And when it comes to applications where there are a lot of operations with large files and audio or video streaming, HTTP / 2 will be slower than its predecessors.

Another con is the poor loading speed of sites via HTTP / 2 through mobile devices using 3G Internet. In the case of 3G, the latency will be over 300 ms and may fluctuate. And HTTP / 2 does not perform well with a long response delay. Under these conditions, HTTP/1.1 will be faster than HTTP/2.

In summary, HTTP/2 should be used for sites with SSL, and should not be used if you need to work with audio and video streams or large files.

Which factor has the most influence on website speed?

The presence of third-party scripts, all kinds of pop-ups, which slow down website work in Google Tag Manager

What to do with pop-ups that greatly slow down the initial page load?

Such pop-ups are loaded by default along with the main elements of the page. They negatively affect the Core Web Vitals settings and are not needed by the user from the very beginning. They also do not carry useful content that Google could evaluate for SEO.

The best way out is to simply delay loading them until the first screen has fully loaded and is interactive. That is, when the parameters of Core Web Vitals have already been calculated, and the user begins to interact with the page. The loading of such elements can simply be delayed by a timer that is available in Google Tag Manager, for example, for 6 seconds.

What is LCP and how can it be improved?

Largest Contentful Paint (LCP) is the amount of time the browser takes to render the largest element of a website page visible on the first screen of devices. It should load as early as possible relative to the rest of the page elements.

This can be a text box, an image, or an input box. This element may differ even for the same page when loaded on devices with different screen resolutions. Depends on how much of the page will be on the first screen.

Google Chrome browser detects LCP from users and sends measurements to Google servers. These measurements can be viewed in the browser in the developer console, under the Performance and Lighthouse tabs. A simple way to determine the largest element on the first screen is the standard PageSpeed ​​Insights. At the bottom of the recommendations, it is explicitly stated that the LCP is calculated during the test.

How to speed up the first rendering of content?

First Contentful Paint is the first rendering of meaningful page content. To speed it up, you need to improve everything that can be affected by hosting. You also need to delay the loading of everything that the user will not need in the first second, for example, analytics counters and Facebook Pixel. If this is not done, the site will take too long to load, and not only Google, but also visitors may not like it.

Cumulative layout shift - how to detect it?

Cumulative layout shift (CLS) is the movement of page elements from place to place while it is loading. For example, the text is loaded first, and only then the picture is loaded, which shifts all the text down. You can detect CLS in the Google Chrome console in the Performance tab or using any online tool that takes screenshots of page loading.

To avoid layout shift, each element should have its own reserved area where it will appear. You can also use placeholders - gray rectangles that inform the user that content will appear at this place soon, and you need to wait.

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