Improve Your AI-Built Website Speed Before Launch

Test the Website

Do not start randomly optimizing files. First create a baseline so you know what is actually slow and whether the changes improve it.

Use a browser performance tool such as Chrome Lighthouse, or Google PageSpeed Insights for an already deployed website.

Google PageSpeed Insights

Test an already-deployed website's real-world mobile and desktop performance.

https://pagespeed.web.dev

Test both:

Mobile Desktop

Pay attention to:

Page load speed Large images Layout shifts Slow-loading fonts JavaScript work Unused resources Network requests Third-party scripts

NOTE

Do not chase a perfect score. Focus first on problems that noticeably affect real users.

Run the Performance Audit

Performance & Loading-Speed Audit

Inspects the codebase for oversized or poorly formatted images, unnecessary JavaScript, unused dependencies, expensive rendering, blocking fonts, layout shifts, slow third-party scripts, and dev-only code shipped to production — changes nothing, ranks findings by impact, and finishes with the responsible file/component and the smallest safe fix for each high-impact issue plus a short optimization plan.

Review this entire website specifically for performance and loading-speed problems. Do not change anything yet. Inspect the codebase and identify the biggest performance problems across important pages. Check for: - unnecessarily large images - images served at much larger dimensions than they are displayed - missing lazy loading where appropriate - poor image formats or compression - unnecessary JavaScript - large client-side bundles - unused dependencies - duplicated libraries - expensive components or rendering - unnecessary re-renders - content loaded before it is needed - slow or excessive third-party scripts - blocking font loading - too many font files or font weights - layout shifts caused by missing dimensions - large background images - unnecessary animations - slow API requests that block important UI - assets loaded globally that are needed only on specific pages - development-only code included in production Also inspect the production build configuration. Do not redesign the website. Do not remove features just to improve a performance score. Do not make broad refactors unless they are genuinely necessary. Rank your findings as: 1. High impact 2. Medium impact 3. Low impact For every high-impact issue, tell me: - what is slow - why it matters - the file/component responsible - the smallest safe fix Finish with a short optimization plan.

Optimize Images First

Start with the improvements most likely to make a noticeable difference. AI-built websites often contain images that are much larger than necessary. Check:

Hero images Product images Gallery images Background images Thumbnails Logos

Use appropriate dimensions and formats without making the images visibly poor.

IMPORTANT

Do not lazy-load the main above-the-fold image if that would delay the most important visual content.

Optimize the Code & Apply the Fixes

Then address genuine code-level problems.

Apply High-Impact Performance Fixes

Applies the audit's high-impact fixes with the smallest safe changes — image sizing and optimization, lazy loading, reducing JavaScript and unused dependencies, font loading, layout shifts, animations, and third-party code — without redesigning, removing functionality, or hurting SEO, accessibility, auth, forms, analytics, or payments, then runs the production build and tests and lists every change with its expected improvement.

Apply the high-impact performance fixes from the audit. Use the smallest safe changes and preserve the existing design and functionality. Prioritize: - properly sizing large images - using appropriate image optimization supported by this project - lazy-loading below-the-fold images and content where appropriate - preventing unnecessary assets from loading on every page - reducing unnecessary JavaScript - removing genuinely unused dependencies or imports - splitting heavy code when it provides a meaningful benefit - reducing unnecessary component re-renders - improving font loading - reducing unnecessary font weights/files - preventing avoidable layout shifts - reducing expensive or unnecessary animations - delaying non-critical third-party code where safe Do not: - redesign the website - remove important functionality - aggressively optimize code that is already fine - replace the project's framework - introduce a large new performance library without a clear reason - convert the entire codebase to a different architecture Be especially careful not to hurt: - image quality - SEO content - accessibility - authentication - forms - analytics - payments - mobile usability After the changes: - run the production build - run relevant tests - check for runtime errors Finish with: High-impact optimization: COMPLETE / NEEDS REVIEW Then list exactly what changed and what improvement each change is expected to provide.

Review Fonts

Once the obvious problems are fixed, check the resources that load around the page. Avoid loading fonts or weights that the website never uses.

For example, if the design only uses:

Regular Medium Bold

you may not need six additional weights.

NOTE

But do not replace the site's typography unnecessarily.

Review Third-Party Scripts

Review scripts for services such as:

Analytics Chat widgets Tracking Embeds Maps Videos Social widgets

Some third-party scripts are useful but do not always need to block the initial page load.

Run the Loading-Behavior Audit

Loading-Behavior Optimization Pass

Reviews fonts, font weights, icons, analytics, third-party scripts, embeds, maps, chat widgets, and route-specific resources for anything that can safely load later, lazy-load, load only where needed, or be removed if genuinely unused — preserves all business functionality and above-the-fold content, runs the production build, and answers Loading optimization: COMPLETE, NO CHANGES NEEDED, or NEEDS REVIEW.

Perform a second performance pass focused only on loading behavior. Review: - web fonts - font weights - icons - analytics scripts - third-party scripts - embedded videos - maps - chat widgets - external widgets - heavy components - route-specific code - resources loaded globally Identify anything that can safely be: - loaded later - lazy-loaded - loaded only on the page that needs it - removed if genuinely unused Preserve all important business functionality. Do not remove analytics, forms, tracking, payments, or other working integrations merely because they add network requests. Optimize how they load when appropriate instead. Also check that important above-the-fold content is not being delayed unnecessarily. Make only changes with a clear performance benefit. Run the production build afterward. Finish with: Loading optimization: COMPLETE / NO CHANGES NEEDED / NEEDS REVIEW

Test Important Pages Again

Now test the same pages again. Use the same tool and similar conditions you used in Step 1. Compare the before and after results instead of judging the final score in isolation. Do not test only the homepage — depending on the website, also check pages such as:

Landing page Product/service page Pricing Dashboard Booking page Contact page Other high-traffic pages

Run the Final Performance & Regression Audit

Final Performance & Regression Audit

Verifies the production build succeeds, important pages and navigation still work, images/fonts/lazy-loading display correctly, forms/auth/analytics/payments still work if used, mobile layouts are unchanged or improved, no console or network errors were introduced, and nothing SEO- or accessibility-critical was broken — identifies any remaining genuinely worthwhile fix, and answers Performance status: READY or NOT READY.

Run a final performance and regression audit after these optimizations. Verify: - the production build succeeds - important pages still work - navigation works - images display correctly - important above-the-fold content loads correctly - lazy-loaded content appears when expected - fonts display correctly - forms still work - authentication still works if used - analytics/tracking still works if used - payments still work if used - mobile layouts are unchanged or improved - no new browser console errors were introduced - no important network requests are failing - no SEO-critical content was accidentally removed or hidden - no accessibility-critical functionality was broken Also identify any remaining performance issue that is genuinely worth fixing before launch. Do not make additional speculative optimizations. Finish with: Performance status: READY / NOT READY If NOT READY, list only the remaining high-impact problems.

Compare Before & After

Run Lighthouse or PageSpeed Insights again. Compare:

Mobile performance

Desktop performance

Loading experience

Major warnings

Image sizes

JavaScript/network usage

The goal is not necessarily a score of 100. The goal is a website that loads quickly, feels responsive, and keeps all of its important functionality.