5 Common LCP Mistakes That Are Killing Your Site Speed
Most poor LCP scores don't come from one dramatic problem — they come from a handful of small, repeated mistakes that quietly add up. Here are the five most common ones, and how to fix them.
Key takeaways:
- Oversized hero images are the single most common LCP problem
- Web fonts and third-party scripts often delay rendering more than businesses realize
- Lazy-loading your LCP image can backfire and slow it down
- Slow hosting sets a ceiling on how fast LCP can ever be, regardless of other fixes
- Fixing these mistakes usually requires no redesign, just configuration changes
Mistake 1: Oversized, Uncompressed Hero Images
A 4,000-pixel-wide banner image uploaded straight from a camera or stock site, without resizing or compression, is often the single biggest LCP offender on a page.
The fix: Resize images to the actual display dimensions, convert to modern formats like WebP or AVIF, and compress before uploading.
Mistake 2: Lazy-Loading the LCP Element
It's common practice to lazy-load images so they only load as the visitor scrolls to them. But applying this to the hero image — the one visible immediately — delays exactly the element you need to load fastest.
The fix: Never lazy-load the image or video that's likely to be your LCP element; consider preloading it instead.
Mistake 3: Render-Blocking Web Fonts
Custom fonts that must fully download before any text can render will delay LCP if that text is part of the largest visible element.
The fix: Use font-display: swap, preload critical font files, and limit the number of font weights/styles loaded.
Mistake 4: Too Many Third-Party Scripts
Chat widgets, heatmap trackers, ad tags, and social media embeds each add extra network requests and processing time, competing with your main content for bandwidth and browser resources.
The fix: Audit every third-party script on your site and remove or defer any that aren't essential to the initial page experience.
Mistake 5: Slow Hosting or No CDN
If your server takes over a second just to respond to the initial request, no front-end optimization can fully compensate — everything downstream is delayed before it even starts.
The fix: Use a reputable host with good Time to First Byte (TTFB) performance, and serve static assets through a CDN so they load from servers closer to your visitors.
Quick Reference Table
| Mistake | Symptom | Fix |
|---|---|---|
| Oversized images | Large LCP element, slow render | Resize, compress, use modern formats |
| Lazy-loaded hero image | Delayed LCP despite fast page | Preload instead of lazy-load |
| Blocking web fonts | Text-based LCP delayed | font-display: swap, preload fonts |
| Excess third-party scripts | Inconsistent, spiky LCP | Audit and remove non-essential scripts |
| Slow hosting/no CDN | High baseline LCP everywhere | Upgrade hosting, add a CDN |
Frequently Asked Questions
Which of these mistakes is most common?
Oversized hero images, by a wide margin — they're the easiest mistake to make and often the highest-impact fix once corrected.
Can I fix these without a developer?
Image optimization and font settings can often be handled through your CMS or a plugin. Server and hosting changes typically need developer or hosting-provider involvement.
How do I know which mistake is affecting my site?
Run your page through PageSpeed Insights — it identifies your specific LCP element and flags which of these issues is contributing to the delay.
Next Steps for Your Business
Check your LCP element in PageSpeed Insights and compare it against the five mistakes above. Most sites find at least one immediately actionable fix.
Our team can audit your site for these exact issues and fix them without a full redesign.