How to Check Website Loading Speed and Where to Do It

Website speed usually becomes noticeable only when the problem is already clear: pages open slowly, ads bring visitors but not leads, the mobile version takes too long to respond, or PageSpeed Insights shows red scores. In reality, website loading speed should be checked regularly — after launch, redesign, new sections, integrations, plugins, analytics scripts, or advertising tools are added.

Speed is not just a technical metric for developers. It affects how users perceive your business, whether they wait for a page to open, whether they click a button, submit a form, complete a purchase, or come back later. For Google, speed is also part of the overall page experience, so it should not be separated from SEO, website structure, mobile usability, and content quality.

In this article, we will look at how to check website speed correctly, which tools to use, why different tools show different results, which metrics matter most, and what to do after the test.

Why Website Loading Speed Matters for Business

A slow website rarely looks like one single big issue. More often, it appears as a set of small symptoms: the hero banner takes too long to appear, the form opens with a delay, buttons do not react immediately, product images load slowly, or the mobile version feels heavy.

For a website owner, this may not seem critical. But for a user, every extra second reduces trust and motivation to continue.

Speed is especially important for pages that are supposed to generate leads: landing pages, catalogs, e-commerce pages, service pages, quiz pages, SEO blog articles, and pages used in paid advertising campaigns. If a page loads slowly, a business may lose potential clients before they even see the offer.

Website speed affects:

• first impression of the company;
• bounce rate;
• form and button conversions;
• Google Ads performance;
• mobile user experience;
• technical SEO;
• user behavior on the page.

That is why, during website technical support, speed should not be checked separately from stability, security, analytics, forms, responsive design, and SEO basics. Very often, the problem is not one large image but the overall technical condition of the website.

What “Website Speed” Actually Means

Many people see speed as a single number: “the site loads in 2 seconds” or “PageSpeed shows 68 points.” In practice, speed consists of several stages.

When a user opens a page, the browser contacts the server, receives HTML, loads CSS, JavaScript, fonts, images, builds the page, displays the first content, and makes the page interactive. A delay can happen at any of these stages.

That is why it is important to look not only at total loading time but also at what exactly happens while the page is loading.

Server Response

This is how quickly the server starts sending the page. If the server responds slowly, even a well-optimized frontend will not fully solve the issue. The reasons may include weak hosting, heavy database queries, poor caching, an overloaded CMS, or backend logic problems.

First Content Display

For the user, the most important thing is not when every script has finished loading, but when they see something useful: a headline, the first screen, an image, text, menu, or button. If the page stays blank for several seconds, this creates a poor experience.

Loading of the Main Visible Block

For a service page, this may be the hero section with the main offer. For a product page, it may be the image, title, price, and purchase button. For a blog article, it is the headline and first paragraph.

This is where LCP matters. LCP shows how quickly the largest visible element on the screen appears.

Readiness for Interaction

Sometimes a page already looks loaded, but buttons still do not respond or respond with a delay. This often happens on websites with a lot of JavaScript, sliders, animations, third-party widgets, and advertising scripts.

This is where INP matters. It shows how quickly the page responds to user actions.

Visual Stability

Sometimes a page seems loaded, but elements shift: a button moves, a banner appears late, text jumps after a font loads, or an ad block pushes content down. This hurts the user experience and may lead to accidental clicks.

This is measured by CLS, which shows how visually stable the page is.

Where to Check Website Loading Speed

To evaluate speed properly, it is better not to rely on only one tool. One tool will show a general score, another will show technical reasons, another will help analyze real browser behavior, and another will show real user experience.

Below are the main tools worth using.

Google PageSpeed Insights

Google PageSpeed Insights is one of the most popular tools for checking website speed. It is useful because it shows separate results for mobile and desktop versions, Core Web Vitals, optimization recommendations, and issues that may affect user experience.

It is important to understand that PageSpeed Insights is not just a “good” or “bad” score. It combines lab data and field data. Lab data is collected in controlled conditions and is useful for diagnostics. Field data is based on real user experience, but it is not always available for every page.

What to Look at in PageSpeed Insights

First of all, do not focus only on the 0–100 score. Look at specific metrics:

• LCP — how quickly the main content appears;
• INP — how quickly the page reacts to interactions;
• CLS — whether elements shift during loading;
• FCP — when the first content appears;
• TTFB — how quickly the server responds.

PageSpeed is useful for initial diagnostics, but it should not be treated as the only source of truth. A website may have a less-than-perfect score and still work well for users. And the opposite is also possible: a website may feel fast on desktop but have serious issues on mobile.

Lighthouse in Chrome DevTools

Lighthouse is an audit tool that can be launched directly in Chrome DevTools. It evaluates not only performance but also accessibility, SEO, best practices, and general page quality.

This tool is especially useful for developers because it allows them to quickly check a page after code changes. For example, after optimizing images, removing an unnecessary script, changing fonts, or rebuilding a section, Lighthouse helps show whether the result has improved.

When to Use Lighthouse

Lighthouse is useful:

• during development of a new page;
• after redesign;
• after adding new sections;
• after installing analytics, pixels, or widgets;
• before launching advertising;
• after speed optimization.

Lighthouse is good for technical testing, but results may vary from one test to another. That is why it is better to run several tests and look at the overall trend, not just one random score.

Chrome DevTools: Network Tab

Chrome DevTools is not only for developers. Even a website owner or marketer can open the Network tab and see which resources take the longest to load.

There you can check:

• which images are too heavy;
• how many requests the page makes;
• whether fonts load slowly;
• which scripts block the page;
• whether there are 404 errors;
• which files are the largest.

This is useful when PageSpeed shows a general issue, but you need to find the exact reason. For example, the website may be slow not because of “bad code,” but because of one large image in the first screen, an incorrect image format, or a third-party widget.

GTmetrix

GTmetrix is useful for visual loading analysis. It shows a waterfall chart — the order in which page resources are loaded. This helps understand what exactly delays the page: server response, CSS, JavaScript, images, fonts, third-party services, or analytics.

GTmetrix is often used to compare results before and after optimization. For example, if images were compressed, caching was added, unnecessary scripts were removed, or the first screen was optimized, GTmetrix clearly shows how the loading structure has changed.

WebPageTest

WebPageTest is a strong tool for deeper speed testing. It allows you to test a website from different locations, devices, and connection types. This is especially important if the website serves users from different regions or countries.

For example, a website may load quickly in your office on fast internet but work slowly for a mobile user or someone from another region. WebPageTest helps identify such differences.

This tool is worth using when you need not just a general score, but a professional performance audit.

Google Search Console

Google Search Console is not a classic tool for checking the speed of a single page, but it is important for SEO. In its reports, you can see Core Web Vitals issues for groups of pages. This is useful if the website has many URLs: blog pages, catalog pages, products, categories, or services.

The advantage of Search Console is that it helps you see the overall picture, not just one random URL. For example, you may discover that the issue is not only on the homepage, but on all product pages because the product template contains heavy images or unnecessary scripts.

Google Analytics

Google Analytics does not replace PageSpeed or Lighthouse, but it helps understand the business impact of speed. Technical metrics are important, but it is even more important to see how real users behave.

After checking speed, it is worth analyzing:

• whether slow pages have a high bounce rate;
• whether mobile traffic converts worse;
• whether users drop off on specific pages;
• whether traffic from ads behaves differently from organic traffic;
• whether users leave during checkout or form submission.

For an e-commerce website, this is especially important because a slow product page, category, cart, or checkout can directly affect sales.

The Most Important Website Speed Metrics

Not all metrics are equally important for business. Some are needed by developers for diagnostics, others are useful for SEO specialists, and some directly reflect user experience.

LCP: Loading of the Main Content

LCP shows when the largest important element appears on the screen. Usually, it is a large image, banner, heading block, or the main part of the first screen.

If LCP is poor, the user waits too long before seeing the main content. In practice, this often means that the hero section needs optimization: image weight should be reduced, fonts should be loaded correctly, server response should be improved, or render-blocking resources should be removed.

INP: Website Response Speed

INP shows how quickly the website responds to user actions: clicking a button, opening a menu, entering text into a form, selecting a filter, or interacting with an interface element.

Poor INP often appears on websites with too much JavaScript, heavy animations, complex filters, sliders, or third-party scripts. For users, this feels like the website is loaded but still slow and uncomfortable to use.

CLS: Page Stability

CLS shows whether elements move while the page is loading. This matters for usability. If a user wants to click a button, but a banner suddenly appears and moves it, this creates frustration.

The most common causes of poor CLS are:

• images without defined dimensions;
• late font loading;
• banners inserted after the main content;
• ad blocks without reserved space;
• dynamic elements that change the page height.

TTFB: Server Response Speed

TTFB shows how long it takes to receive the first byte from the server. If it is high, you need to check hosting, caching, database performance, backend logic, CMS settings, or server configuration.

For WordPress, OpenCart, or WooCommerce websites, high TTFB is often connected with heavy plugins, lack of caching, an overloaded database, or weak hosting. For custom websites, the reasons may include API calls, server-side rendering, inefficient database queries, or external integrations.

Why PageSpeed Shows Different Results

One of the most common situations is this: you run a test today and get 82 points. One hour later, you get 74. The next day, you get 88. It may seem like the tool is unstable, but in reality, speed depends on many factors.

Results may differ because of:

• server load at the moment of testing;
• response time of third-party services;
• different mobile and desktop testing conditions;
• browser or server cache;
• advertising scripts;
• fonts, videos, maps, chats, or widgets;
• the difference between lab and field data.

That is why you should not make conclusions after one test. It is better to check the page several times, compare mobile and desktop versions, and look not only at the score but also at specific recommendations.

How to Check Website Speed Correctly

For the test to be useful, you need a systematic approach. Simply entering a URL into PageSpeed is only the first step.

1. Check More Than the Homepage

The homepage is often better optimized than other pages. But real leads may come from service pages, product pages, categories, or blog articles. That is why you need to check different types of pages:

• homepage;
• service page;
• product page;
• category page;
• blog article;
• advertising landing page;
• form or checkout page.

For a corporate website, it is especially important to check not only the homepage but also key service pages, because they often rank in Google and receive warm traffic.

2. Analyze the Mobile Version Separately

Mobile speed is often worse than desktop speed. This is normal, but it does not mean the issue can be ignored. Most users browse from phones, and mobile internet or weaker devices reveal technical problems more clearly.

If the desktop PageSpeed score is 90 and the mobile score is 45, you should focus on the mobile version. The issue is often related to hero images, heavy fonts, JavaScript, sliders, video, or a poorly built first screen.

3. Run Several Tests

One test does not always show the full picture. It is better to run 3–5 checks at different times and look at the average result. If the same issue appears repeatedly, it definitely needs attention.

4. Compare Pages With Each Other

It is useful to test several pages of the same website. If all pages are slow, the issue is likely systemic. If only one page is slow, the reason may be a specific section, image, video, or script.

5. Save Results Before and After Optimization

Before making any changes, save the current results. After optimization, run the test again. This helps understand whether the changes actually improved performance.

Common Reasons Why a Website Loads Slowly

A slow website does not always mean that hosting must be changed or the entire website rebuilt from scratch. Often, the reasons are simpler — but they need to be found correctly.

Heavy Images

This is one of the most common problems. Images are often uploaded in large sizes, without compression, in the wrong format, or without adaptive versions for mobile devices.

This is especially critical when a heavy image is placed in the first screen. It directly affects LCP and makes the website feel slow.

Too Much JavaScript and CSS

A page may load many scripts that are not needed on that specific URL. For example: a slider, map, popup, chat, analytics, pixel, animation library, and several extra modules. Each of them adds weight and may block rendering.

Weak Hosting or Server

If the server responds slowly, frontend optimization will only help partially. In this case, TTFB, caching, PHP or Node.js version, database performance, CDN, server logs, and load should be checked.

No Caching

Caching allows the website to avoid generating the same page from scratch every time. For CMS-based websites, this is especially important. Without caching, the server may waste time processing every request.

Poor Font and Third-Party Resource Setup

A beautiful font can slow down a website if it is loaded incorrectly. The same applies to maps, chats, CRM forms, videos, trackers, advertising scripts, and external widgets.

Outdated Design or Technical Structure

Sometimes a website is slow not because of one mistake, but because the entire technical foundation is outdated. An old template, unnecessary sections, poor structure, outdated plugins, and heavy layout can create a systemic problem.

In this case, it may be worth thinking not only about point optimization but also about a website redesign, especially if the current website structure already limits growth.

What to Do After Checking Website Speed

The speed test itself does not change anything. Its value is in helping you define priorities correctly.

You do not need to fix everything at once. Start with what affects users and business the most. If the first screen of a landing page loads slowly, work on LCP first. If users cannot interact comfortably with the menu, filters, or forms, look at INP. If the page jumps during loading, fix CLS.

Basic Action Plan

1. Check key pages in PageSpeed Insights.
2. Compare mobile and desktop versions.
3. Look at LCP, INP, CLS, and TTFB.
4. Open Chrome DevTools and find the heaviest resources.
5. Check whether the issue appears across several page templates.
6. Create a priority task list.
7. Make changes and run the test again.

This approach is better than simply trying to “raise PageSpeed to 100.” A perfect score is not always necessary. What matters more is that the website opens quickly for real users, does not lose leads, and does not have critical technical issues.

Should You Aim for 100 Points in PageSpeed?

A 100-point PageSpeed score is nice, but it is not always a reasonable goal. For a simple landing page, it may be realistic. For an e-commerce website, a site with filters, user accounts, payments, CRM integrations, analytics, and complex functionality — not always.

It is important not to turn optimization into a chase for numbers. If you remove important trust elements, forms, analytics, or useful functionality just to reach 100 points, the business may lose more than it gains.

It is better to ask:

• does the user see the main content quickly;
• is the page easy to interact with;
• do elements stay stable;
• are there no critical errors;
• does the website lose leads because of slow loading;
• are mobile results stable enough?

Speed is important, but it works together with content, structure, design, technical SEO, trust, and conversion logic.

How Often Should You Check Website Speed?

Website speed should not be checked only once after launch. It should be monitored regularly, especially if the website is actively growing and new articles, pages, products, banners, scripts, integrations, popups, advertising pixels, or forms are added.

A good approach is to check speed:

• after website launch;
• after redesign;
• after adding new pages;
• before launching ads;
• after installing new modules or plugins;
• after changing hosting;
• after major SEO updates;
• once every 1–2 months for active projects.

For websites that generate leads from Google or paid ads, speed testing should be part of regular technical control, not a one-time action.

Conclusion

Checking website loading speed is not just about running a PageSpeed Insights test. It is a full diagnostic process that shows how the website works for real users: how quickly the first screen appears, whether users can interact with the page immediately, whether elements shift, whether unnecessary scripts slow things down, and whether the business loses leads because of technical issues.

The best approach is to use several tools: PageSpeed Insights for a general overview, Lighthouse for audits, Chrome DevTools for technical diagnostics, GTmetrix or WebPageTest for deeper analysis, Search Console for the SEO picture, and Google Analytics for user behavior.

But the most important thing is not just getting a number — it is interpreting it correctly. A slow website does not always need to be rebuilt completely. Sometimes it is enough to optimize images, caching, fonts, scripts, or server response. In other cases, speed becomes a signal that the website is technically outdated and needs a deeper update.

If your website already brings traffic, leads, or sales, speed should be monitored systematically. Every extra second of loading is not just a technical detail — it may be a lost client.

FAQ

Where is the best place to check website loading speed?

For a first check, Google PageSpeed Insights is the most convenient option. It shows mobile and desktop results, Core Web Vitals, and basic recommendations. For a more complete picture, it is also worth using Lighthouse, Chrome DevTools, GTmetrix, or WebPageTest.

Why does PageSpeed show a low score if my website seems fast?

Because PageSpeed does not evaluate only subjective loading speed. It analyzes LCP, INP, CLS, server response, JavaScript, CSS, images, and other technical factors. A website may feel fast on your device but still have issues on weaker devices or mobile internet.

What PageSpeed score is considered good?

The green zone is a good reference point, but the total score is not the only thing that matters. It is more important that key Core Web Vitals are within a good range, the main content loads quickly, and the page does not create problems for users.

Why is the mobile score worse than the desktop score?

Mobile tests are usually stricter. They take into account weaker devices, slower connections, and limited resources. If a website is heavy, has many scripts, large hero images, or unoptimized visuals, the mobile score will usually be much lower.

Does website speed affect SEO?

Yes, speed and page experience can influence search performance, but they are not the only ranking factors. Google also considers relevance, content quality, website structure, technical condition, usability, authority, and many other signals. Speed should be treated as part of comprehensive SEO.

Can I check the speed of a competitor’s website?

Yes, you can check public competitor pages using PageSpeed Insights, GTmetrix, or WebPageTest. However, these results will be approximate because you cannot see their analytics, server logs, real conversions, or user behavior data.

What usually slows down a website?

The most common reasons are heavy images, excessive JavaScript, weak server performance, lack of caching, unoptimized fonts, third-party widgets, plugins, videos, maps, chats, and advertising scripts.

Should all website pages be optimized?

Start with the most important pages: homepage, service pages, product pages, categories, advertising landing pages, and pages that already receive traffic from Google. After that, you can move on to lower-priority URLs.

How do I know that my website needs speed optimization?

If pages open slowly, the mobile PageSpeed score is low, users leave quickly, ads bring clicks without leads, or Search Console shows Core Web Vitals issues, it is a clear signal that speed should be checked and optimized.