Image SEO: 10 Free Tips for Google Images

Good image SEO comes down to helping Google find your images, understand them and load them fast: use a real <img> tag, give the file a descriptive name, write useful alt text, place it near related text, and keep it light. The last part is where most sites fall down, and it's the easiest to fix with the free image compressor and resizer. Here are ten tips, each based on Google's published guidance for Google Images.

These are for anyone with a website: a blog, a shop, a portfolio or a school project site. None needs special software.

1. Use an HTML img element, not a CSS background

Google finds images through the src attribute of <img> elements. Google's documentation says plainly that it doesn't index CSS images. If your product photo or infographic is a background-image in CSS, it won't show up in Google Images. Decorative backgrounds are fine in CSS; anything you want found belongs in an <img>.

2. Give files descriptive names

IMG_20261012_101533.jpg tells Google nothing. Google recommends short, descriptive file names, such as brass-diya-set-of-4.jpg instead of a camera's default. Use hyphens between words, keep it brief, and describe what's in the picture. Rename before uploading, because changing a file name later changes its URL.

3. Write alt text that describes the image in context

Google calls alt text the most important attribute for image metadata, and it's also what screen readers read aloud. Describe what the image shows and why it's on the page:

• Weak: alt="diya"
• Keyword-stuffed: alt="diya diwali diya buy diya online cheap diya"
• Useful: alt="Four brass diyas lit on a wooden table"

Avoid stuffing keywords. Purely decorative images can have an empty alt="".

4. Put images near relevant text

Google uses the text around an image, its caption and the page title to understand it. An image of a recipe step works best right beside that step, not in a gallery at the bottom. A short caption under important images helps both readers and search.

5. Resize to the size it's displayed

A photo straight from a phone is about 4000 pixels wide. If your blog column is 800 pixels wide, a browser downloads all those extra pixels and throws them away. Resize to about the display width, or up to twice that for sharp phone screens, with the free image resizer. This alone often cuts the file size by over 90%.

6. Compress every image

Google notes that images are often the largest contributor to page size, and recommends optimising them for speed. After resizing, run them through the free image compressor: it takes up to 20 images at once, and at 75-80% quality the difference is hard to see. Our guide to compressing images for a website gives size targets by image type.

7. Use modern formats like WebP

Google Images supports BMP, GIF, JPEG, PNG, WebP, SVG and AVIF. WebP files are often noticeably smaller than JPG at the same visible quality. Convert a batch with the free JPG to WebP converter, or choose WebP under Save as in the compressor. Make sure the file extension matches the real format. Our comparison of WebP, PNG and JPG explains when each makes sense.

8. Use srcset, but keep a src fallback

Responsive images (srcset or <picture>) let phones download a smaller version. Google's guidance is to always include a normal src as a fallback, because some browsers and crawlers don't understand the newer attributes.

<img src="diya-800.webp"
     srcset="diya-400.webp 400w, diya-800.webp 800w, diya-1600.webp 1600w"
     sizes="(max-width: 800px) 100vw, 800px"
     alt="Four brass diyas lit on a wooden table"
     width="800" height="600">

Making the three sizes takes a minute in the resizer: resize to 1600, 800 and 400 pixels wide, saving each as WebP. The width and height attributes reserve space so the page doesn't jump as images load.

9. Help Google find images it might miss

If images load through JavaScript or live on a separate CDN, an image sitemap helps Google discover them. Google also supports structured data for products, recipes and articles, and uses og:image or primaryImageOfPage to pick a preferred image for a page. These are worth doing on shops and recipe sites; a simple blog can skip them.

10. Choose good images in the first place

Sharp, relevant, original images are what people click on. Google suggests avoiding text-heavy images or logos as the main picture for a page, and prefers normal aspect ratios. Crop away clutter with the free image cropper so the subject fills the frame. A 16:9 or 4:3 crop usually looks best in search results and social previews.

A quick checklist before publishing

Check	Done when
File name	Describes the image, words separated by hyphens
Alt text	One plain sentence about what it shows
Dimensions	About the display width, at most twice
Format	WebP or JPG for photos; PNG or SVG for logos and diagrams
File size	Most photos under about 200 KB
Markup	<img> with src, alt, width and height

The 200 KB figure is a rule of thumb, not a Google limit. Smaller is faster.

Do it now

Rename your files, resize them to the width they're shown at, and run the whole batch through the free image compressor, choosing WebP or JPG. Your images are processed on your own device, so even unreleased product photos stay private.