Improve LCP, INP, and CLS for Web Performance 2025

If your site is slow, you’re leaving traffic and revenue on the table. Core Web Vitals are no longer optional. Google has made them a ranking factor, meaning publishers that ignore them risk losing visibility, traffic, and user trust. For those of us working in SEO and digital publishing, the message is clear: speed, stability, and responsiveness directly affect performance. Core Web Vitals focus on three measurable aspects of user experience: → Largest Contentful Paint (LCP): How quickly the main content loads. Target: under 2.5 seconds. → First Input Delay (FID) / Interaction to Next Paint (INP): How quickly the page responds when a user interacts. Target: under 200 milliseconds. → Cumulative Layout Shift (CLS): How visually stable a page is. Target: less than 0.1. These metrics are designed to capture the “real” experience of a visitor, not just what a developer or SEO sees on their end. Why publishers can't ignore CWV in 2025 1. SEO & Trust: Only ~47% of sites pass CWV assessments, presenting a competitive edge for publishers who optimize now. 2. Page performance pays off: A 1-second improvement can boost conversions by ~7% and reduce bounce rates—benefits seen across industries 3. User expectations have tightened: In 2025, anything slower than 3 seconds feels “slow” to most users—under 1 s is becoming the new gold standard, especially on mobile devices. 4. Real-world wins: a. Economic Times cut LCP by 80%, CLS by 250%, and slashed bounce rates by 43%. b. Agrofy improved LCP by 70%, and load abandonment fell from 3.8% to 0.9%. c. Yahoo! JAPAN saw session durations rise 13% and bounce rates drop after CLS fixes. Practical steps for improvement • Measure regularly: Use lab and field data to monitor Core Web Vitals across templates and devices. • Prioritize technical quick wins: Image compression, proper caching, and removing render-blocking scripts can deliver immediate improvements. • Stabilize layouts: Define media dimensions and manage ad slots to reduce layout shifts. • Invest in long-term fixes: Optimizing server response times and modernizing templates can help sustain improvements. Here are the key takeaways ✅ Core Web Vitals are measurable, actionable, and tied directly to SEO performance. ✅ Faster, more stable sites not only rank better but also improve engagement, ad revenue, and subscriptions. ✅ Publishers that treat Core Web Vitals as ongoing maintenance, not one-time fixes will see compounding benefits over time. Have you optimized your site for Core Web Vitals? Share your results and tips in the comments, your insights may help other publishers make meaningful improvements. #SEO #DigitalPublishing #CoreWebVitals #PageSpeed #UserExperience #SearchRanking

Introducing Insights in Chrome DevTools Performance panel! Many web developers know the power of the Chrome DevTools Performance panel, but navigating its wealth of data to pinpoint issues can be daunting. While tools like Lighthouse provide great summaries, they often lack the context of when and where issues occur within a full performance trace. On the Chrome team we're bridging this gap with the new "Insights sidebar" directly within the Performance panel. Read all about it: https://lnkd.in/gGd3bkPw This exciting feature integrates Lighthouse-style analysis right into your workflow. After recording a performance trace, the Insights sidebar appears, offering actionable recommendations. Crucially, it doesn't just list potential problems but highlights relevant events and overlays explanations directly on the performance timeline. Hover over an insight like "LCP by phase," "Render blocking requests" or "Layout shift culprits" to visually connect the suggestion to the specific moments in your trace. The sidebar covers key areas like Largest Contentful Paint (LCP) optimization (including phase breakdowns and request discovery), Interaction to Next Paint (INP) analysis (like DOM size impact and forced reflows), Cumulative Layout Shift (CLS) culprits, and general page load issues such as third-party impact and image optimization. It's designed to make performance debugging more intuitive by linking high-level insights to the granular data, helping you improve Core Web Vitals and overall user experience more effectively. Check out the Insights sidebar in the latest Chrome versions (it's been evolving since Chrome 131!). It’s a fantastic step towards making complex performance analysis more accessible. Give it a try on your next performance audit! #softwareengineering #programming #ai

The Truth About Website Speed Tests Most tools are lying to you. Want to know why your site's still slow? Because you're using the wrong tools... In the wrong way... And focusing on the wrong metrics. Let me show you what actually works: ✅ The Only Speed Tools That Matter Forget the fancy dashboards. These are your new best friends: → Google PageSpeed Insights (Because Google actually uses this) → GTmetrix (For the technical deep dive) → WebPageTest (For real-world testing) Everything else? Nice to have, but not essential. ✅ The Metrics That Actually Impact Revenue Stop obsessing over "page load time." Focus on these instead: → Largest Contentful Paint (LCP) Must be under 2.5 seconds → Time to First Byte (TTFB) Keep it under 200ms → Cumulative Layout Shift (CLS) Below 0.1 or customers bounce ✅ The Action Steps That Work Most tools give you a list of 50+ things to "fix." Here's what actually moves the needle: ✨ Compress those massive images ✨ Upgrade your cheap hosting ✨ Use a solid CDN ✨ Enable browser caching ✨ Lazy load everything else Real companies saw real results... A Brisbane e-commerce site: • Cut load time from 6.2s to 1.8s • Reduced bounce rates by 21% • Boosted conversions by 14% ✅ The Monitoring That Matters Don't trust single tests. Test from multiple: • Locations • Devices • Time periods Because one good score doesn't mean your site's actually fast. The Truth? Your website speed is probably worse than you think. But here's the good news: You don't need perfect scores. You need real-world performance that: • Keeps visitors engaged • Reduces bounce rates • Drives more sales Stop chasing perfect scores. Start chasing perfect performance. Because in 2025... Speed isn't just about fast loading. It's about faster revenue. Do you agree? :)

𝗛𝗼𝘄 𝗜 𝗢𝗽𝘁𝗶𝗺𝗶𝘇𝗲𝗱 𝗠𝘆 𝗥𝗲𝗮𝗰𝘁 𝗔𝗽𝗽 𝗣𝗲𝗿𝗳𝗼𝗿𝗺𝗮𝗻𝗰𝗲 𝗨𝘀𝗶𝗻𝗴 𝗖𝗵𝗿𝗼𝗺𝗲 𝗗𝗲𝘃𝗧𝗼𝗼𝗹𝘀🚀 Last week, my React app was feeling sluggish. Here's exactly how I used 𝗖𝗵𝗿𝗼𝗺𝗲 𝗗𝗲𝘃𝗧𝗼𝗼𝗹𝘀 𝗣𝗲𝗿𝗳𝗼𝗿𝗺𝗮𝗻𝗰𝗲 𝗽𝗮𝗻𝗲𝗹 to fix it: Step 1: Open Performance Panel Press Ctrl+Shift+I (or Cmd+Option+I on Mac) → Click "Performance" tab Step 2: Check Core Web Vitals The panel immediately showed me my LCP, CLS, and INP scores. My React component renders were causing poor LCP! 😱 Step 3: Compare with Real Users Clicked "Set up" in Field Data section to fetch Chrome UX Report data. Turns out, my local environment was WAY faster than what users experienced. Step 4: Match User Conditions DevTools suggested throttling CPU and network. This revealed the real bottlenecks - heavy re-renders and large bundle sizes in my React components. Step 5: Record & Analyze Hit the record button, interacted with my app, and stopped. The flame chart showed exactly which React components were causing performance issues. 𝙏𝙝𝙚 𝙍𝙚𝙨𝙪𝙡𝙩? - Identified unnecessary re-renders with useMemo and useCallback - Lazy-loaded heavy components with React.lazy() - Improved LCP by 40%! 𝗣𝗿𝗼 𝘁𝗶𝗽 𝗳𝗼𝗿 𝗥𝗲𝗮𝗰𝘁 𝗱𝗲𝘃𝘀: The Performance panel works seamlessly with React DevTools Profiler for even deeper insights into component rendering. Stop guessing, start measuring! 📈 #ReactJS #WebPerformance #JavaScript #FrontendDevelopment #ChromeDevTools #WebDev #ReactOptimization

Web Core Vitals Checklist 1. Largest Contentful Paint (LCP) - Load LCP within 2.5 seconds for all pages. - Remove unnecessary third-party scripts: Each script can slow the page by 34 ms. - Upgrade your web host for faster overall load times. - Avoid lazy loading images above the fold to prevent increasing LCP time. - Remove large, unnecessary elements from above the fold to speed up LCP. - Minify your CSS to reduce delays in LCP. 2. Interaction to Next Paint (INP) - Aim for INP of 200 milliseconds or less. - Optimize JavaScript to reduce delays in interaction. - Defer non-essential JavaScript. - Remove non-critical third-party scripts that may affect INP. - Defer code execution by breaking down long tasks into smaller chunks. 3. Cumulative Layout Shift (CLS) - Keep CLS score below 0.1. - Use set size attributes for images and videos to prevent layout shifts. - Reserve space for ad elements to avoid unexpected content shifts. - Avoid adding new content above the fold dynamically, such as banners, to maintain page stability. - Use transform animations instead of layout-affecting animations. 4. General Optimization - Enable compression (GZIP, Brotli). - Use a Content Delivery Network (CDN). - Cache assets to reduce server load. - Optimize CSS, JavaScript, and HTML code. - Regularly monitor performance using tools like Google PageSpeed Insights. - Prioritize content quality and user experience over a single score 5. Mobile-Friendliness - Ensure responsive design. - Optimize touch targets and font sizes. - Test on multiple devices and screen sizes. 6. Security - Implement HTTPS. - Regularly update all software and plugins. - Use strong security headers. 7. Tools to Use - thruuu - WP Rocket - Layout Shift GIF Generator - Airlift - GTmetrix  - Lighthouse - PageSpeed Compare - Cloudflare  - WebP converter for Media P.S. Did I Miss Something? Share your thoughts 👇 .................................................. Repost ♻️ to help others Hit the 🔔 to get notified Follow Nitin Mathur 🎨 ..................................................... #CoreWebVitals #WebPerformance #PageSpeed WebDev #FrontEndOptimization #UX #WebVitals

How do you improve frontend performance? Most candidates say: “Optimize images…” “Reduce JS…” Good answers. But not great ones. Top candidates answer with Web Vitals 👇 1️⃣ Largest Contentful Paint (LCP) → How fast the main content loads → Target: < 2.5s → Improve by: preloading critical assets, optimizing images, using CDN 2️⃣ Interaction to Next Paint (INP) (replacing FID) → How fast the UI responds to user actions → Target: < 200ms → Improve by: breaking long JS tasks, code splitting, debouncing handlers 3️⃣ Cumulative Layout Shift (CLS) → Visual stability of the page → Target: < 0.1 → Improve by: reserving space for images, avoiding layout shifts 4️⃣ First Contentful Paint (FCP) → When the first content appears → Target: < 1.8s → Improve by: reducing render-blocking resources, inlining critical CSS 5️⃣ Time to First Byte (TTFB) → Server response time → Target: < 800ms → Improve by: caching, backend optimization, CDN 6️⃣ Total Blocking Time (TBT) → How long the main thread is blocked → Target: < 200ms → Improve by: reducing JS execution, splitting bundles, removing unused code 💡 How to answer this in an interview (senior-level): “I measure performance using Web Vitals like LCP, INP, CLS, along with FCP, TTFB, and TBT. Then I identify bottlenecks using Lighthouse and Chrome DevTools. Based on that, I optimize loading, interactivity, and stability.” That’s the difference between: Knowing optimizations vs thinking like an engineer. What’s your go-to performance optimization in real projects? 👇 #Frontend #WebPerformance #React #JavaScript #SoftwareEngineering #CodingInterview

Wait... Passing Core Web Vitals isn't fast enough??? For years I've helped brands "get to green", and passing Google's site speed target has become the default web performance goal for most websites. This week I was shocked to learn that at this speed, most brands are still leaving SIGNIFICANT money on the table. Site speed directly influences business outcomes. A faster site results in: - Lower bounce rates - Higher conversion rates - And therefore higher revenues, healthier business, happier customers. New real-world eCommerce performance data from across 700+ brands and 500M+ shopper sessions shows that continuing to optimize beyond Google's recommended targets, continues to boost conversion, and drop bounce rates. For LCP ("Looks fast") - Passing CWV (2.5s): average 1.49% conversion rate and 60.51% bounce rate - Conversion rates across all sessions, brands, device types, and platforms peak at 1.3s - Sessions at 1.3s average 2.21% conversion, and 44.64% bounce rate! Shaving 1.2 seconds off LCP, above and beyond Google's recommendation, shows a 26% lower bounce rate, and 48% higher conversion rate! The data also shows that optimizing LCP beyond 1.3s LCP shows diminishing returns, and becomes exceptionally expensive. And for INP ("Feels fast") - Conversion rate continues to improve all the way to 0ms INP.  - Driving INP to 0ms from Google's recommended 200ms results in 16.3% higher conversion rate - Bounce rate at 100ms INP is 10.3% lower than at Google's 200ms threshold. This is shocking to me, honestly. We have a lot of work to do! Explore for yourself at the link in the comments. #sitespeed #webperf #ecommerce #conversion #analytics #pagespeed #corewebvitals

If your team ships AI-generated frontend code without performance gates, you are silently degrading the experience your users depend on, one deploy at a time. 𝘞𝘦𝘣 𝘗𝘦𝘳𝘧𝘰𝘳𝘮𝘢𝘯𝘤𝘦 𝘌𝘯𝘨𝘪𝘯𝘦𝘦𝘳𝘪𝘯𝘨 𝘪𝘯 𝘵𝘩𝘦 𝘈𝘨𝘦 𝘰𝘧 𝘈𝘐 by Addy Osmani combines deep technical insight with case studies and modern optimization techniques, grounded in current browser internals. The core premise: speed and resilience are non-negotiable, regardless of whether the code was human-authored or LLM-generated. 𝗧𝗵𝗲 𝘁𝗿𝘂𝘀𝘁 𝗲𝗾𝘂𝗮𝘁𝗶𝗼𝗻 A slow or unstable experience drives users away, and when AI coding assistants accelerate output velocity, the risk of shipping unoptimized code to real users scales silently with it. ⚠️ 𝗪𝗵𝗮𝘁 𝗵𝗼𝗹𝗱𝘀 𝘂𝗽 𝗶𝗻 𝗽𝗿𝗮𝗰𝘁𝗶𝗰𝗲 🔹 Measure Core Web Vitals per deploy, not per sprint. AI-generated code can introduce layout shifts and render-blocking resources that only surface under real device conditions and network profiles. 🔹 Profile rendering pipelines before optimizing. The book ties every technique to how browsers actually process, paint, and composite, so your bottleneck analysis targets root causes instead of surface-level symptoms. 🔹 Enforce performance thresholds as release gates in CI. If your pipeline does not fail on LCP or CLS regressions, AI-assisted development velocity becomes a liability, not an advantage. ⚙️ 𝗙𝗮𝗶𝗹𝘂𝗿𝗲 𝗺𝗼𝗱𝗲 𝘁𝗼 𝘁𝗿𝗮𝗰𝗸 🔹 The book assumes code from Cursor, Copilot, or ChatGPT still requires dedicated performance validation. Teams that skip this review on AI-generated PRs accumulate invisible technical debt that compounds at scale. 🔍 𝗦𝗵𝗶𝗽 𝗴𝗮𝘁𝗲 𝗳𝗼𝗿 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝗼𝗻 𝗿𝗲𝗮𝗱𝗶𝗻𝗲𝘀𝘀 𝗦𝗽𝗲𝗲𝗱: LCP, FID, and CLS within threshold on real devices, not lab environments only. 𝗦𝘁𝗮𝗯𝗶𝗹𝗶𝘁𝘆: No layout shift regressions introduced by new AI-generated components. 𝗗𝗲𝗯𝘂𝗴𝗴𝗮𝗯𝗶𝗹𝗶𝘁𝘆: Bottleneck traces map to specific rendering phases, not vague slowness reports. 𝗦𝗰𝗮𝗹𝗲: Optimizations hold across device tiers and under real-world load conditions. 𝗔𝗰𝗰𝗼𝘂𝗻𝘁𝗮𝗯𝗶𝗹𝗶𝘁𝘆: Performance budgets enforced in CI with automated regression alerts on every merge. If your team uses AI coding assistants for frontend work, what is your current gate for catching performance regressions before they reach production? 🎯 #WebPerformance #AIGeneratedCode #CoreWebVitals #FrontendEngineering #PerformanceOptimization #LLMAssistedDev #ContinuousIntegration #PerformanceBudgets #BrowserInternals #TechLeadership #AI #AICoding