PocketSEOCut Largest Contentful Paint by Preloading the Hero Image
PocketSEO Editorial @pocketseo
Key Takeaway
Your hero image is usually the LCP element, so preload it and set fetchpriority high to make your main content paint well under 2.5 seconds.
What does Largest Contentful Paint measure?
Largest Contentful Paint (LCP) measures how long it takes for the biggest element in the viewport to render. On most pages that element is the hero image, a large banner, or a headline block. LCP marks the moment your main content actually appears to the visitor.
It is one of the three Core Web Vitals and the clearest proxy for the question every user asks: does this page feel fast?
What is a good LCP score?
A good LCP is 2.5 seconds or less. According to Google, pages should hit 2.5 s at the 75th percentile of visits, while anything over 4 seconds is rated poor. The clock starts the moment the user requests the page.
Most LCP failures share one cause: the hero image loads too late because the browser discovers it too slowly.
How does preloading the hero image cut LCP?
Preloading tells the browser to fetch your hero image right away, before it finds the image in CSS or further down the HTML. By default, browsers discover background images and below-the-fold assets late, which pushes the paint back.
Add a preload hint in the <head>:
<link rel="preload" as="image" href="/hero.webp" fetchpriority="high">The fetchpriority="high" attribute does the heavy lifting. It tells the browser this image outranks other downloads, so it jumps to the front of the queue instead of waiting behind scripts and fonts.
What else speeds up LCP?
Preloading helps most when you pair it with these steps:
- Never lazy-load the LCP image. Remove
loading="lazy"from the hero. Lazy loading delays the one image you want to arrive first. - Serve modern formats. Use WebP or AVIF and compress hard. Smaller files paint sooner.
- Set explicit dimensions. Add
widthandheightso the browser reserves space and skips a re-layout. - Use a CDN. A shorter network hop means the image lands faster.
Add fetchpriority="high" directly on the <img> tag too, so the priority hint still applies if the preload is missed. Test before and after in PageSpeed Insights, then confirm the win in field data over the next few weeks.
Want the full playbook? Read our guide on Technical SEO Audits: Which Fixes to Prioritize First.