{"id":11703,"date":"2026-05-05T13:59:31","date_gmt":"2026-05-05T10:59:31","guid":{"rendered":"https:\/\/digitalpro.gr\/?p=11703"},"modified":"2026-05-05T13:59:31","modified_gmt":"2026-05-05T10:59:31","slug":"ergaleia-metrisis-tachytitas-istoselidas","status":"publish","type":"post","link":"https:\/\/digitalpro.gr\/en\/ergaleia-metrisis-tachytitas-istoselidas\/","title":{"rendered":"Website speed measurement tools and practical improvement steps"},"content":{"rendered":"

Improving speed does not start with \u201clet me install a plugin\u201d or \u201clet me change hosting\u201d. It starts with correct measurement<\/strong>. If you don't know what exactly<\/em> it is delaying and on which pages<\/em>, it is very easy to make changes that do not bring results or (even worse) create new problems. In this guide we will look at the most useful website speed measurement tools<\/strong>, what each one shows you, and a practical workflow to move from diagnosis \u2192 fixes \u2192 re-checking.<\/p>\n\n\n\n

1) What we are really measuring when we talk about \u201cspeed\u201d<\/h2>\n\n\n\n

\u201cSpeed\u201d isn't just a number. In practice, you measure 3 things:<\/p>\n\n\n\n

    \n
  1. When is the main content displayed?<\/strong> (so that the user does not see a blank screen).<\/li>\n\n\n\n
  2. When can it interact?<\/strong> (clicks, scrolling, forms, filters) without any delay.<\/li>\n\n\n\n
  3. How stable is the page?<\/strong> (Do not move any items whilst it is loading).<\/li>\n<\/ol>\n\n\n\n

    <\/p>\n\n\n\n

    Here you will often come across symbols such as:<\/p>\n\n\n\n

      \n
    • LCP<\/strong> (loading main content),<\/li>\n\n\n\n
    • INP<\/strong> (response to an interaction),<\/li>\n\n\n\n
    • CLS<\/strong> (layout stability),
      and also terms such as TTFB<\/strong> (how quickly the server \u201cresponds\u201d) or total \u201cload time\u201d.<\/li>\n<\/ul>\n\n\n\n

      You don\u2019t need to memorise everything. The aim is to understand Where is the bottleneck?<\/em>: server<\/strong>, files (images\/JS\/CSS\/fonts)<\/strong> or third-party scripts<\/strong>.<\/p>\n\n\n\n

      2) Lab vs Field: why you might see different results<\/h2>\n\n\n\n

      Before we even get to the tools, there\u2019s one point that confuses a lot of people:<\/p>\n\n\n\n

        \n
      • Laboratory data<\/strong>: testing in a controlled environment (under the same conditions every time). Very useful for diagnosis and debugging.<\/li>\n\n\n\n
      • Field data<\/strong>: data from real users (different devices\/networks). Very useful for getting a true picture of the user experience.<\/li>\n<\/ul>\n\n\n\n

        Ideally you want both<\/strong>:<\/p>\n\n\n\n

          \n
        • Lab to find what's the problem?<\/em>,<\/li>\n\n\n\n
        • Field to confirm whether users actually benefited<\/em>.<\/li>\n<\/ul>\n\n\n\n

          3) The basic tools for measuring website speed (and when to use them)<\/h2>\n\n\n\n

          A) Google PageSpeed Insights (PSI)<\/h3>\n\n\n\n

          The PSI is the \u201cquick check\u201d that gives you:<\/p>\n\n\n\n

            \n
          • summary overview,<\/li>\n\n\n\n
          • key findings,<\/li>\n\n\n\n
          • suggestions for improvement.<\/li>\n<\/ul>\n\n\n\n

            When do you use it:<\/strong> when you want an initial audit per page (ideally: home, category, product, checkout\/form, landing page).<\/p>\n\n\n\n

            What to watch out for:<\/strong> Don't get bogged down just on the \u201cscore\u201d. Look which problems keep recurring<\/em> and if it is image-heavy, JS-heavy or server-heavy.<\/p>\n\n\n\n

            B) Lighthouse (via Chrome)<\/h3>\n\n\n\n

            Lighthouse is essentially the \u201cengine\u201d behind many reports. It runs from:
            Chrome \u2192 DevTools \u2192 Lighthouse.<\/p>\n\n\n\n

            When do you use it:<\/strong> when you want recurring lab tests and a more detailed breakdown.<\/p>\n\n\n\n

            What to watch out for:<\/strong> compare before\/after<\/em> changes under the same conditions (incognito, without extensions).<\/p>\n\n\n\n

            C) Chrome DevTools: Network & Performance<\/h3>\n\n\n\n

            If you want to find exactly<\/em> what\u2019s the delay, this is the \u201coperating theatre\u201d.<\/p>\n\n\n\n

            Network tab:<\/strong><\/p>\n\n\n\n

              \n
            • which files are being downloaded,<\/li>\n\n\n\n
            • which is massive,<\/li>\n\n\n\n
            • which ones are blocking the upload,<\/li>\n\n\n\n
            • those provided by third parties.<\/li>\n<\/ul>\n\n\n\n

              Performance tab:<\/strong><\/p>\n\n\n\n

                \n
              • where time is spent in the browser (rendering, scripting),<\/li>\n\n\n\n
              • which scripts do the \u201cheavy lifting\u201d.<\/li>\n<\/ul>\n\n\n\n

                When do you use it:<\/strong> when you have a specific problem and you want to tie it to a cause (e.g., \u201cit\u2019s slow because it\u2019s loading 5MB images\u201d or \u201cit freezes because a script is running for too long\u201d).<\/p>\n\n\n\n

                D) GTmetrix (report + waterfall)<\/h3>\n\n\n\n

                GTmetrix is very useful for more \u201creadable\u201d reports and waterfall.<\/p>\n\n\n\n

                When do you use it:<\/strong> when you want to see clearly:<\/p>\n\n\n\n

                  \n
                • which asset is behind schedule,<\/li>\n\n\n\n
                • which requests are too many,<\/li>\n\n\n\n
                • if there is a \u201cchain\u201d of scripts.<\/li>\n<\/ul>\n\n\n\n

                  Tip:<\/strong> Waterfall is gold. It\u2019ll show you if, for example, a chat widget is generating 10 extra requests and slowing down the interaction.<\/p>\n\n\n\n

                  E) WebPageTest (more advanced test)<\/h3>\n\n\n\n

                  It is one of the most powerful tools for a deep dive, especially if you want to try:<\/p>\n\n\n\n

                    \n
                  • different locations,<\/li>\n\n\n\n
                  • different network speeds,<\/li>\n\n\n\n
                  • multiple repetitions.<\/li>\n<\/ul>\n\n\n\n

                    When do you use it:<\/strong> when you want \u201cproof\u201d under more realistic conditions, or when a website behaves differently depending on the country or network.<\/p>\n\n\n\n

                    F) Google Search Console: Core Web Vitals report<\/h3>\n\n\n\n

                    Here you can see problems at the level URL groups<\/strong> and not just on a single page.<\/p>\n\n\n\n

                    When do you use it:<\/strong> to identify patterns: e.g., \u201call product pages have an issue\u201d, or \u201conly articles with many embeds\u201d.<\/p>\n\n\n\n

                    What you gain:<\/strong> site-wide prioritisation, especially if you have many pages.<\/p>\n\n\n\n

                    4) A practical 5-step workflow (so you don't get lost)<\/h2>\n\n\n\n
                    \"88\"<\/figure>\n\n\n\n

                    Step 1: Choose the \u201cimportant\u201d pages<\/h3>\n\n\n\n

                    Don\u2019t just count at random. Make a short list:<\/p>\n\n\n\n

                      \n
                    • Home<\/li>\n\n\n\n
                    • 1\u20132 categories (if you have an e-shop)<\/li>\n\n\n\n
                    • 1\u20132 products or 1\u20132 core services<\/li>\n\n\n\n
                    • Checkout or form<\/li>\n\n\n\n
                    • 1 landing page from advertisement (if you are running one)<\/li>\n<\/ul>\n\n\n\n

                      Step 2: Take a baseline with 2 tools<\/h3>\n\n\n\n

                      E.g. PageSpeed Insights + GTmetrix<\/strong>. Note:<\/p>\n\n\n\n

                        \n
                      • what is repeated,<\/li>\n\n\n\n
                      • what is the greatest \u201cburden\u201d,<\/li>\n\n\n\n
                      • if the problem is mainly mobile.<\/li>\n<\/ul>\n\n\n\n

                        Step 3: Confirm \u201cwhat is happening to users\u201d<\/h3>\n\n\n\n

                        Have a look at Search Console (Core Web Vitals)<\/strong> where a signal is available.<\/p>\n\n\n\n

                        Step 4: Find 2\u20133 key \u201cculprits\u201d<\/h3>\n\n\n\n

                        They are usually:<\/p>\n\n\n\n

                          \n
                        • images\/videos,<\/li>\n\n\n\n
                        • third-party scripts,<\/li>\n\n\n\n
                        • heavy JS,<\/li>\n\n\n\n
                        • slow TTFB (server),<\/li>\n\n\n\n
                        • fonts\/layout shifts.<\/li>\n<\/ul>\n\n\n\n

                          Step 5: Make one change at a time and measure again<\/h3>\n\n\n\n

                          The most common mistake: making 10 changes at once and then saying, \u201cI don\u2019t know which one worked\u201d.
                          Keep a record (even a simple Word document): change \u2192 result \u2192 next step.<\/p>\n\n\n\n

                          5) Improvements by problem category (If you see this \u2192 do this)<\/h2>\n\n\n\n
                          \"2148909052\"<\/figure>\n\n\n\n

                          If you see \u201cdisturbing images\u201d<\/h3>\n\n\n\n

                          Symptoms:<\/strong> large file transfers, slow LCP, delayed image loading.
                          What do you do (in order):<\/strong><\/p>\n\n\n\n

                            \n
                          • correct dimensions (not 4000px for a 900px display),<\/li>\n\n\n\n
                          • modern formats (e.g. WebP),<\/li>\n\n\n\n
                          • compression,<\/li>\n\n\n\n
                          • lazy loading for content below the fold,<\/li>\n\n\n\n
                          • pay attention to sliders\/hero images (they are usually the \u201cLCP element\u201d).<\/li>\n<\/ul>\n\n\n\n

                            If you see \u201cmany third-party scripts\u201d<\/h3>\n\n\n\n

                            Symptoms:<\/strong> numerous requests to third-party domains, slow response times, \u201cfreezes\u201d.
                            What are you doing?<\/strong><\/p>\n\n\n\n

                              \n
                            • keep only what you really need,<\/li>\n\n\n\n
                            • load the non-critical ones later (defer\/delay),<\/li>\n\n\n\n
                            • prioritise: analytics is fine, but 3 chat widgets are not.<\/li>\n<\/ul>\n\n\n\n

                              If you come across \u201cheavy JavaScript\u201d<\/h3>\n\n\n\n

                              Symptoms:<\/strong> Long scripting time, low INP, lag when clicking or scrolling.
                              What are you doing?<\/strong><\/p>\n\n\n\n

                                \n
                              • remove unnecessary components\/animations,<\/li>\n\n\n\n
                              • severely restricted plugins,<\/li>\n\n\n\n
                              • Check for page builders that load lots of scripts everywhere.<\/li>\n<\/ul>\n\n\n\n

                                If you notice a \u201cslow server \/ high TTFB\u201d<\/h3>\n\n\n\n

                                Symptoms:<\/strong> Loading is slow to start, even though the files are small.
                                What are you doing?<\/strong><\/p>\n\n\n\n

                                  \n
                                • page caching,<\/li>\n\n\n\n
                                • object cache where necessary,<\/li>\n\n\n\n
                                • hosting\/resource check,<\/li>\n\n\n\n
                                • database optimisation (especially in CMS),<\/li>\n\n\n\n
                                • CDN for static files.<\/li>\n<\/ul>\n\n\n\n

                                  If you see \u201clayout shifts\u201d (CLS)<\/h3>\n\n\n\n

                                  Symptoms:<\/strong> Buttons and text move as it loads.
                                  What are you doing?<\/strong><\/p>\n\n\n\n

                                    \n
                                  • defining dimensions in images\/embeds,<\/li>\n\n\n\n
                                  • watch out for fonts (swap behaviour),<\/li>\n\n\n\n
                                  • avoiding banners \u201coverlapping\u201d existing content without space.<\/li>\n<\/ul>\n\n\n\n

                                    6) WordPress: the most common areas that can be improved<\/h2>\n\n\n\n

                                    If the site is WordPress, the classic \u201cthemes\u201d are:<\/p>\n\n\n\n

                                      \n
                                    • many plugins that load scripts on all pages,<\/li>\n\n\n\n
                                    • a heavy theme\/page builder,<\/li>\n\n\n\n
                                    • incorrect\/incomplete caching,<\/li>\n\n\n\n
                                    • images uploaded without optimisation,<\/li>\n\n\n\n
                                    • Too many third-party scripts (pop-ups, reviews, chat).<\/li>\n<\/ul>\n\n\n\n

                                      What is usually worth looking at first:<\/strong><\/p>\n\n\n\n

                                        \n
                                      1. caching (properly configured),<\/li>\n\n\n\n
                                      2. images,<\/li>\n\n\n\n
                                      3. reduction\/restriction of third-party scripts,<\/li>\n\n\n\n
                                      4. cleaning up plugins,<\/li>\n\n\n\n
                                      5. hosting check\/TTFB.<\/li>\n<\/ol>\n\n\n\n

                                        7) Mini checklist of priorities (a quick guide to \u201cwhat to do first\u201d)<\/h2>\n\n\n\n
                                          \n
                                        • I\u2019ve counted 5\u20136 key pages (mobile & desktop)<\/li>\n\n\n\n
                                        • I'm checking whether the problem is images, scripts or server<\/li>\n\n\n\n
                                        • Optimising hero\/LCP images<\/li>\n\n\n\n
                                        • I limit third-party scripts (keeping only those that are essential)<\/li>\n\n\n\n
                                        • I\u2019m setting up proper caching<\/li>\n\n\n\n
                                        • I check fonts and layout stability<\/li>\n\n\n\n
                                        • I repeat the measurements after every change<\/li>\n<\/ul>\n\n\n\n

                                          Conclusion<\/h2>\n\n\n\n

                                          The correct ones website speed measurement tools<\/strong> They protect you from \u201cblind\u201d changes and guide you towards targeted improvements. Start with a baseline, review the findings calmly, identify 2\u20133 key culprits and work through them step by step, checking as you go. In this way, speed becomes a process that delivers results, rather than a constant source of stress.<\/p>\n\n\n\n

                                          \ud83d\udc49 Return to the overview: The importance of speed on your website<\/em>
                                          \ud83d\udc49 Regarding how it affects business\/SEO: How fast loading affects sales and SEO<\/em><\/p>\n\n\n\n

                                          <\/p>","protected":false},"excerpt":{"rendered":"

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