How to Optimize Images for Google (Image SEO Guide)

Images influence search in two ways: they can rank on their own in Google Images and image-rich results, and they affect how fast — and therefore how well — your pages perform. This checklist covers both.

1. Use real HTML images

Google indexes images referenced with <img> elements (including inside <picture>). Images applied only as CSS backgrounds are not indexed as images. Anything that should be found should be an <img>.

2. Write descriptive file names

IMG_4821.jpg tells nobody anything. red-trail-running-shoe-side.jpg describes the image for search engines and people alike. Use lowercase words separated by hyphens; keep it short and accurate.

3. Write useful alt text

Alt text is read by screen readers and used by search engines to understand the image. Describe what the image shows in the context of the page:

• Good: alt="Red trail running shoe with a grippy rubber sole, side view"
• Bad: alt="shoe shoes running shoes buy shoes cheap"

Decorative images should have an empty alt="" so screen readers skip them.

4. Put images near relevant text

Captions and surrounding paragraphs help Google understand an image. An image inside an article about the subject carries more meaning than one in a generic gallery.

5. Choose efficient formats

Smaller images load faster, which improves Largest Contentful Paint. Google Search supports AVIF, WebP, JPEG, PNG, GIF, BMP and SVG. Serve AVIF or WebP with a JPEG fallback — read the best image format for websites — and convert with JPG to WebP or JPG to AVIF.

6. Serve the right size

Provide several widths with srcset and sizes so each device downloads what it needs, and always set width and height to prevent layout shift. Resize Image handles batches.

7. Lazy-load — carefully

loading="lazy" delays offscreen images until the user scrolls near them. Never lazy-load the main (LCP) image; give it fetchpriority="high" instead.

8. Add structured data where it fits

Product, recipe, article and other structured data types can include an image property, which makes your images eligible for richer results. Only mark up what is visible on the page.

9. Include images in your sitemap

For important images that might not be discovered easily, add them to your XML sitemap with the image extension, or make sure the pages that contain them are in your sitemap.

10. Use high-quality social images

Open Graph images (og:image) are not a ranking factor, but they determine how your pages look when shared. 1200 × 630 pixels is the common size.

11. Strip metadata — but keep the colour profile

EXIF data does not help rankings and can leak private information such as GPS coordinates. Remove it with the metadata remover; it keeps the ICC colour profile so colours stay accurate.

Quick checklist

• <img> elements with descriptive file names
• Meaningful alt text; empty alt for decorative images
• AVIF/WebP with fallback, quality 75–85
• srcset/sizes, width/height
• LCP image not lazy-loaded
• Structured data and sitemap coverage
• Metadata removed

Want to see what your images carry before you publish them? Check them in the image metadata viewer.