Image SEO Audit

Paste page URLs or crawl your whole site to check every image: file size, broken files, alt text, width and height, lazy-loading, srcset and file format. Each problem is listed with the pages it appears on, so you know exactly what to fix first.

How to audit your images

1. Choose Pages and paste up to 50 page URLs, or choose Whole site and enter your homepage.
2. Click Audit images. The tool reads every image tag on the pages, then checks each image file’s status, size and type.
3. Work through the Issues list from the top. Each issue shows the images and the pages they are on.
4. Use the Images table to filter by issue, search by URL or alt text, and tap an image to see every page that uses it.
5. Download the Images and Issues CSVs to share with whoever updates your site.

What to fix first

• Broken images. Fix the file path or remove the image.
• Very large files. Resize them to the width they are shown at, then compress. Our image compressor does both in your browser and can convert to WebP.
• Missing alt text on images that matter, such as products, services and charts. Describe what the image shows in a short sentence.
• Missing width and height, so the page doesn’t jump while images load.
• Lazy-loading: lazy-load images further down the page, but not the main image at the top.

Good to know

• Images added with CSS backgrounds or by JavaScript after the page loads are not included, because the tool reads the HTML your server sends.
• Size thresholds (150 KB and 500 KB) are rules of thumb, not Google rules. A large hero photo can be fine if it is well compressed and not lazy-loaded.

Want a full technical check as well? Run the website SEO crawler.

Frequently asked questions

What does the image audit check?

For every image it reads the HTML tag (alt text, width and height, loading=”lazy”, srcset or picture) and checks the file itself: status code, file size from the server’s Content-Length header and file type. It flags broken files, heavy images, missing or unhelpful alt text, missing dimensions, lazy-loading mistakes, JPEG/PNG/GIF that could be WebP or AVIF, insecure http images and unhelpful file names.

How big should my images be?

There is no official limit. As a rule of thumb, most photos used in page content can be under 150 KB once they are resized to the width they are shown at and compressed. Anything over 500 KB is almost always worth shrinking, especially for visitors on mobile data.

Is empty alt text a problem?

Not always. alt=”” is the correct way to mark a purely decorative image so screen readers skip it. It is a problem when the image carries meaning, such as a product photo, chart or button. A missing alt attribute is different: then screen readers may read out the file name.

Should every image be lazy-loaded?

No. Lazy-load images further down the page, but load the main image near the top straight away. Lazy-loading the first, largest image can delay Largest Contentful Paint.

Why is the size of some images unknown?

The size comes from the Content-Length header the image server sends. Some servers and CDNs leave it out. Those images are counted as size unknown and are not treated as an issue.

How many images can it check?

Live audits check the file sizes of up to 500 images from up to 50 pages or a 500-page crawl. For bigger sites, choose Whole site and get the report by email: we crawl up to 1,000 pages on our server and check up to 1,000 images.

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