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LCP Image Optimizer

Check hero images for size, preload and responsive image issues before you publish.

Drop a hero image here or click to browse

The check runs locally. Your image is not uploaded.

Hero image check

Compare the source image size against the display width used on the page.

Preload hints

Get practical loading, fetch priority and preload suggestions for above-the-fold images.

Responsive output

Generate starting picture-tag and srcset markup for modern image delivery.

How to optimize an LCP image

  1. Drop the hero, banner or main above-the-fold image onto the page
  2. Enter the approximate display width used on your layout
  3. Review the resize, preload, fetchpriority and responsive image recommendations

Optimize the image that affects LCP

The Largest Contentful Paint image is often the hero image, banner image, product image or main above-the-fold visual. If that image is much larger than it displays, lazy-loaded by mistake, or missing responsive versions, the page can feel slower than it needs to.

The LCP Image Optimizer checks the source image against the display width you enter and gives practical recommendations: resize targets, responsive widths, whether to lazy load, whether to use fetch priority, and example markup.

LCP IMAGE CHECKLIST

  • Resize the source close to the largest display size actually needed
  • Generate responsive widths for mobile, tablet and desktop
  • Use WebP or AVIF where possible
  • Do not lazy-load the likely above-the-fold LCP image
  • Add width and height attributes to reduce layout shift
  • Use preload carefully for the final hero image source

When to use this instead of a normal compressor

A normal compressor reduces file size. This tool helps you decide what the browser should load in the first place. For LCP, a 300 KB image at the right dimensions can be better than a 180 KB image that still starts late or uses the wrong responsive source.

Issue Recommendation
Hero image is 4000px wide but displays at 1200px Resize before compressing
Main above-the-fold image is lazy-loaded Use eager loading instead
One large image is used for every device Create responsive widths and a srcset
Old JPG/PNG is used for a hero image Create WebP or AVIF versions

Pair it with your existing image tools

After you know the right target width, use Resize Image to scale the file down, then use Compress Image or Convert to WebP for the final output.

Important: This tool gives practical front-end recommendations. It does not replace a full Core Web Vitals audit, but it helps fix one of the most common image-related causes of slow above-the-fold rendering.

LCP Image Optimizer FAQ

What is an LCP image?

An LCP image is often the largest visible image above the fold, such as a hero image, banner, product image or main page image.

Should I lazy-load the LCP image?

Usually no. If the image is the main above-the-fold image, lazy loading can delay it. The tool recommends eager loading and high fetch priority for likely hero images.

Does this tool compress the image?

This page analyzes and recommends sizes and markup. Use Resize Image, Convert to WebP or Compress Image after you know the target dimensions.

Are my images uploaded?

No. The image is read locally in your browser. Nothing is uploaded to CompressImage.ca.