10 Common Website Performance Mistakes (And How to Fix Them)
A practical list of common performance issues that slow down websites and simple ways to solve them.
Performance is not a luxury — it’s a competitive advantage. Slow websites lose conversions, drop in SEO rankings, and frustrate users. The good news: most performance problems come from a handful of predictable mistakes. In this article, we cover the 10 most common issues and how to fix them immediately.
1. Large, unoptimized images
Images are often the biggest files on your page.
**Fix:** • Use Next.js `next/image` • Convert to WebP or AVIF • Compress using Imagify or Squoosh • Lazy-load below-the-fold images
2. Too much JavaScript
Large JS bundles slow parsing and execution.
**Fix:** • Reduce client-side JS • Convert components to Server Components • Remove unused libraries and polyfills
3. Blocking third-party scripts
Analytics, ads, and widgets often block rendering.
**Fix:** • Load scripts with `lazyOnload` • Remove unnecessary trackers • Use server-side analytics where possible
4. No caching or CDN usage
Serving everything from the origin slows down global users.
**Fix:** • Use Vercel Edge or Cloudflare CDN • Leverage caching headers • Cache static assets aggressively
5. Layout shifts (bad CLS)
Unexpected movement makes a site feel broken.
**Fix:** • Predefine width/height for images • Avoid injecting elements without space • Preload web fonts
6. Slow server response (TTFB)
A slow backend delays everything.
**Fix:** • Move dynamic pages to serverless or edge • Cache server responses • Optimize database queries
7. Hydrating too many components
Hydration is expensive and blocks interactivity.
**Fix:** • Use server components wherever possible • Lazy-load client components • Prefer static rendering for content pages
8. Overuse of animations & effects
Heavy animations hurt performance on mobile.
**Fix:** • Use CSS animations where possible • Avoid JS-driven animations • Reduce motion on low-power devices
9. Excessive API calls
Fetching too much data slows down rendering and wastes bandwidth.
**Fix:** • Cache API responses • Fetch only what you need • Combine requests when possible
10. Not monitoring performance
If you don’t measure performance, you can’t improve it.
**Fix:** Use tools like: • Lighthouse • PageSpeed Insights • WebPageTest • Vercel Analytics
to catch regressions early.
Final thoughts
Most performance bottlenecks come from predictable mistakes that are easy to fix once identified. By optimizing images, reducing JavaScript, using caching, and relying more on server rendering, you can dramatically improve load times and user experience. At OpenMeta, performance is not an afterthought — it’s part of our core engineering philosophy.