{"id":21670,"date":"2020-01-28T15:02:00","date_gmt":"2020-01-28T15:02:00","guid":{"rendered":"https:\/\/www.arimetrics.com\/glosario-digital\/wpo"},"modified":"2026-09-28T07:10:17","modified_gmt":"2026-09-28T07:10:17","slug":"wpo","status":"publish","type":"encyclopedia","link":"https:\/\/www.arimetrics.com\/en\/digital-glossary\/wpo","title":{"rendered":"WPO"},"content":{"rendered":"<p><img decoding=\"async\" class=\"boxpad alignright wp-image-13749 size-full\" src=\"https:\/\/www.arimetrics.com\/wp-content\/uploads\/2020\/01\/wpo-1.png\" alt=\"WPO\" width=\"300\" height=\"300\" style=\"margin-top:0;\" srcset=\"https:\/\/www.arimetrics.com\/wp-content\/uploads\/2020\/01\/wpo-1.png 300w, https:\/\/www.arimetrics.com\/wp-content\/uploads\/2020\/01\/wpo-1-150x150.png 150w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><strong>Definition:<\/strong><\/p>\n<p><strong>WPO<\/strong>, an acronym for <em>Web Performance Optimization<\/em>, is the set of techniques used to improve the performance of a website or web application. It covers how quickly content is delivered and displayed, responsiveness during interaction, and the visual stability of the interface.<\/p>\n<p>Performance depends on the server, network, browser, device, code, and resources required by each page. <strong>WPO is not about obtaining an isolated score<\/strong>, but about identifying what limits the experience, applying changes, and checking their effect under representative conditions.<\/p>\n<p>A technical improvement can make a website easier to use and reduce waiting, but it does not guarantee longer visits, conversions, or organic rankings. These outcomes also depend on the content, intent, offer, design, and other factors.<\/p>\n\n<h2>What WPO measures<\/h2>\n<p>Loading speed is one part of performance, but it does not describe the whole process. A page may display content quickly but respond slowly to the first click, or load rapidly while moving elements as a person tries to use them.<\/p>\n<p><a href=\"https:\/\/web.dev\/articles\/vitals\" target=\"_blank\" rel=\"noopener\">Core Web Vitals<\/a> define common metrics for loading, responsiveness, and visual stability. <strong>These five areas provide a more precise view of the journey:<\/strong><\/p>\n<ul>\n<li><strong>Server response:<\/strong> the time needed to establish the connection and begin receiving information, related to metrics such as <a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/ttfb\">TTFB<\/a>.<\/li>\n<li><strong>Main content display:<\/strong> when the most important visible element appears, represented by Largest Contentful Paint or LCP.<\/li>\n<li><strong>Responsiveness:<\/strong> the delay between an interaction and the next visual update, assessed in Core Web Vitals through Interaction to Next Paint or INP.<\/li>\n<li><strong>Visual stability:<\/strong> unexpected movement of text, images, or controls during loading, summarised through Cumulative Layout Shift or CLS.<\/li>\n<li><strong>Resource and execution cost:<\/strong> transferred volume, request count, long tasks, and the work needed to process CSS, JavaScript, images, and fonts.<\/li>\n<\/ul>\n<p>No single metric explains the complete experience. Diagnosis must relate the values to the loading process, <a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/web-rendering\">web rendering<\/a>, and the interactions a user needs to complete.<\/p>\n<h2>Web performance optimisation techniques<\/h2>\n<p>The appropriate measures depend on the bottleneck detected. <strong>These six areas cover common WPO interventions:<\/strong><\/p>\n<ol>\n<li><strong>Optimise images and video:<\/strong> choose suitable dimensions, resolution, and formats, provide responsive variants, and avoid transferring files larger than their visual representation.<\/li>\n<li><strong>Prioritise critical resources:<\/strong> load the content required for the initial view first and apply <a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/lazy-loading\">lazy loading<\/a> to later resources when this does not delay the main element.<\/li>\n<li><strong>Reduce CSS and JavaScript cost:<\/strong> remove unnecessary code, split bundles, minify files, and schedule execution without blocking the main thread longer than necessary.<\/li>\n<li><strong>Improve the server and network:<\/strong> review processing, queries, redirects, protocols, and delivery proximity. A <a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/cdn\">CDN<\/a> can reduce certain distances and distribute resources, but it does not fix a slow application by itself.<\/li>\n<li><strong>Configure caching and compression:<\/strong> define <a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/cache\">cache<\/a> policies, version resources, and use Brotli or gzip when appropriate to avoid repeated or unnecessary transfers.<\/li>\n<li><strong>Control fonts and third parties:<\/strong> limit font variants, reserve space, and assess tags, players, advertisements, or external scripts whose cost the site does not fully control.<\/li>\n<\/ol>\n<p>Combining every CSS or JavaScript file does not always improve the outcome, particularly with modern protocols and routes that need different resources. Likewise, the <code>async<\/code> and <code>defer<\/code> attributes change script downloading and execution, but <strong>do not guarantee that JavaScript will load last or that content will appear first<\/strong>.<\/p>\n<p>Images do not account for a fixed percentage of every page&#8217;s weight. They must be measured for each template and device, paying particular attention to the main image and avoiding lazy loading for a resource that needs to appear immediately.<\/p>\n<h2>Evaluation tools and methods<\/h2>\n<p>Performance can be assessed through field data obtained from real visits and laboratory tests run under controlled conditions. <strong>The two perspectives complement each other:<\/strong> real data shows the experience observed, while laboratory testing supports reproduction and diagnosis.<\/p>\n<p>Four commonly used tools and sources are:<\/p>\n<ul>\n<li><strong><a href=\"https:\/\/pagespeed.web.dev\/\" target=\"_blank\" rel=\"noopener\">PageSpeed Insights<\/a>:<\/strong> combines available field data from Chrome UX Report with a Lighthouse-based laboratory test.<\/li>\n<li><strong><a href=\"https:\/\/developer.chrome.com\/docs\/lighthouse\/overview\/\" target=\"_blank\" rel=\"noopener\">Lighthouse<\/a>:<\/strong> runs reproducible audits and generates metrics and diagnostic opportunities for a specific page.<\/li>\n<li><strong><a href=\"https:\/\/developer.chrome.com\/docs\/devtools\/performance\/\" target=\"_blank\" rel=\"noopener\">Chrome DevTools Performance<\/a>:<\/strong> supports inspection of the network, rendering, main-thread tasks, and interactions during a recording.<\/li>\n<li><strong>Chrome UX Report and <a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/google-search-console\">Google Search Console<\/a>:<\/strong> provide aggregated real-world experience data when a sufficient sample exists, by URL or page group depending on the tool.<\/li>\n<\/ul>\n<p>A laboratory score can vary between runs because of the network, simulated device, server load, and third-party services. <strong>Comparisons need to preserve the same conditions and examine the underlying metrics<\/strong>, not only the overall number.<\/p>\n<p>Evaluation should cover relevant templates and journeys, not only the home page. It may also need to check navigation, direct entries, authenticated pages, and states that load different content or components.<\/p>\n<h2>Relationship between WPO, user experience, and SEO<\/h2>\n<p>WPO relates to page experience but does not represent the whole <a href=\"https:\/\/www.arimetrics.com\/en\/digital-glossary\/ux\">user experience<\/a>. <strong>These four distinctions prevent effects from being attributed to performance when it cannot demonstrate them by itself:<\/strong><\/p>\n<ul>\n<li><strong>Usability:<\/strong> a fast interface can still be confusing, inaccessible, or difficult to operate.<\/li>\n<li><strong>Commercial outcomes:<\/strong> improving a technical metric does not prove that sales or conversions increase; the journey must be measured and other simultaneous changes separated.<\/li>\n<li><strong>SEO:<\/strong> Google uses Core Web Vitals within systems related to page experience, but content relevance and other signals also contribute to <a href=\"https:\/\/www.arimetrics.com\/en\/seo-agency-spain\">SEO rankings<\/a>.<\/li>\n<li><strong>Technical capacity:<\/strong> the best achievable outcome depends on hosting, architecture, third-party providers, and the functional requirements of each project.<\/li>\n<\/ul>\n<p>The operational target should be defined by template, audience, and device. An improvement may reduce a specific delay without changing every metric, while a higher score may not solve the issue affecting the main journey.<\/p>\n<p><strong>WPO is a continuous process of measurement, diagnosis, and improvement.<\/strong> Its value comes from relating each change to an observed limitation and verifying the outcome both in controlled tests and, where possible, in real-world data.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>What WPO is, what it measures, how it optimises images, code, servers and resources, and how it is evaluated with Core Web Vitals and current tools.<\/p>\n","protected":false},"author":7,"featured_media":79673,"template":"","encyclopedia-tag":[1268],"class_list":["post-21670","encyclopedia","type-encyclopedia","status-publish","has-post-thumbnail","hentry","encyclopedia-tag-web-performance"],"_links":{"self":[{"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/encyclopedia\/21670","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/encyclopedia"}],"about":[{"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/types\/encyclopedia"}],"author":[{"embeddable":true,"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/users\/7"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/media\/79673"}],"wp:attachment":[{"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/media?parent=21670"}],"wp:term":[{"taxonomy":"encyclopedia-tag","embeddable":true,"href":"https:\/\/www.arimetrics.com\/en\/wp-json\/wp\/v2\/encyclopedia-tag?post=21670"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}