{"id":5737,"date":"2026-06-19T17:05:23","date_gmt":"2026-06-19T11:35:23","guid":{"rendered":"https:\/\/websitespeedy.com\/blog\/?p=5737"},"modified":"2026-06-19T18:04:43","modified_gmt":"2026-06-19T12:34:43","slug":"why-is-my-lcp-so-high-even-after-optimizing-images","status":"publish","type":"post","link":"https:\/\/websitespeedy.com\/blog\/why-is-my-lcp-so-high-even-after-optimizing-images\/","title":{"rendered":"Why Is My LCP Still High After Optimizing Images? 10 Hidden Causes to Fix"},"content":{"rendered":"\n
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TL;DR:<\/strong> \n Optimizing images doesn’t always fix a high LCP score. In this guide, you’ll learn why LCP can remain slow even after image optimization, how to diagnose the underlying issue, and the most effective ways to reduce loading and rendering delays that impact Core Web Vitals.\n <\/p>\n<\/div>\n\n

\n If you’ve already compressed images, converted them to WebP, resized oversized assets, and enabled responsive images, but you’re still seeing a high LCP after optimizing images<\/strong>, you’re not alone.\n<\/p>\n\n

\n This is one of the most common frustrations with Core Web Vitals<\/a>. Many site owners assume images are always the primary cause of poor Largest Contentful Paint scores. While images often contribute to LCP problems, they are far from the only factor.\n<\/p>\n\n

\n In fact, Google<\/a> also shows that Largest Contentful Paint<\/strong> is influenced by multiple stages of the loading process, including server response time, resource discovery, JavaScript execution, CSS rendering, and browser main-thread activity, not just image size.\n<\/p>\n\n

\n The result? You may have perfectly optimized images while your LCP remains stubbornly high. This blog uncovers 10 hidden causes that can keep Largest Contentful Paint high even after image optimization and explains exactly how to fix each one.\n<\/p>\n\n

\n The 10 Hidden Reasons & Fixes of High LCP After Optimizing Images\n<\/h2>\n\n

\n If your LCP is still high after optimizing images, the problem is usually caused by slow server response times, render-blocking CSS, JavaScript execution, delayed resource discovery, or other rendering issues, rather than the image itself.\n<\/p>\n\n

\n \n \n \n Hidden Cause <\/th>\n Impact on LCP <\/th>\n Recommended Fix <\/th>\n <\/tr>\n <\/thead>\n \n \n Slow server response (TTFB)<\/td>\n Delays page loading from the start.<\/td>\n Improve hosting, caching, and CDN usage.<\/td>\n <\/tr>\n\n \n Render-blocking CSS<\/td>\n Prevents content from appearing quickly.<\/td>\n Inline critical CSS and defer non-critical styles.<\/td>\n <\/tr>\n\n \n Heavy JavaScript<\/td>\n Delays rendering and blocks the main thread.<\/td>\n Remove unused JS and defer non-essential scripts.<\/td>\n <\/tr>\n\n \n Delayed LCP resource discovery<\/td>\n Browser finds the LCP element too late.<\/td>\n Preload critical assets and use standard image tags.<\/td>\n <\/tr>\n\n \n Client-side rendering<\/td>\n Content appears only after JavaScript executes<\/td>\n Use SSR, SSG, or hybrid rendering.<\/td>\n <\/tr>\n\n \n Web font loading<\/td>\n Large text may render slowly.<\/td>\n Preload fonts and use font-display: swap.<\/span<\/td>\n <\/tr>\n\n \n Third-party scripts<\/td>\n Consume resources and delay rendering.<\/td>\n Delay or remove unnecessary third-party scripts.<\/td>\n <\/tr>\n\n \n Incorrect lazy loading<\/td>\n Delays loading of the LCP element.<\/td>\n Exclude above-the-fold content from lazy loading.<\/td>\n <\/tr>\n\n \n PageSpeed Insights vs field data differences<\/td>\n Can make LCP appear higher than expected.<\/td>\n Review both lab and real-user performance data.<\/td>\n <\/tr>\n\n \n Network latency and CDN issues<\/td>\n Slow resource delivery to users.<\/td>\n Use a CDN and optimize caching policies.<\/td>\n <\/tr>\n\n \n <\/tbody>\n <\/table>\n\n<\/div>\n\n

\n Key takeaway:<\/strong> If you have high LCP after optimizing images<\/strong>, the issue is usually related to server performance, CSS, JavaScript, or rendering delays, not image size alone.\n<\/p>\n\n

What Is the Largest Contentful Paint (LCP)?<\/h2>\n\n

\n Largest Contentful Paint (LCP)<\/a> is a Core Web Vitals metric that measures how long it takes for the largest visible piece of content on a page to load and become visible to users. In simple terms, it helps determine when visitors can actually see the main content of a page rather than just a blank screen or loading elements.\n<\/p>\n\n

\n Depending on the page layout, the LCP element is typically one of the following:\n<\/p>\n\n