Image SEO checker
Check every image on a page: missing alt text, missing width and height (a cause of layout shift), old formats like JPG and PNG where WebP or AVIF would be smaller, lazy loading and heavy files, with a clear fix for each issue.
How to use the Image SEO Checker
- 1Enter the address of the page to check.
- 2Read the summary: images, missing alt text, missing sizes, lazy-loaded and modern formats.
- 3Filter the list to see only the images with a problem, each with a thumbnail.
- 4Fix them in your CMS, then compress heavy images with the free Image Compressor.
Frequently asked questions
What makes good alt text?
A short, specific description of what the image shows and why it's there, such as "Barista pouring latte art in our Leeds café". Skip "image of", and use alt="" for purely decorative images.
Why should images have width and height?
With both set, the browser reserves the right space before the image loads, so text doesn't jump down. That keeps Cumulative Layout Shift, a Core Web Vital, low.
Should every image be lazy-loaded?
No. Lazy-load images below the first screen, but never the main hero image: lazy-loading it delays Largest Contentful Paint.
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