Image SEO: Best Practices & Tips That Affect Your Ranking

Image SEO Tips You Need to Know to Improve Your Search Ranking

Images are more than decoration. If you get image SEO right, you’re not just making your site look better - you’re helping it climb search rankings.

Done wrong? You’re slowing your pages down and missing opportunities.

This guide keeps it simple and tells you exactly how to optimise your images for SEO.

Whether you run a shop, a blog, or something else entirely, these tips will help you improve your search visibility with smarter use of images.

1. Why do images affect SEO at all?

Let’s start with the basics.

Search engines can’t “see” images the way humans do. They rely on signals - file names, image alt text, file size, placement, and more - to understand them.

Images affect SEO in these ways:

• They change how fast your pages load, which affects ranking

• They add context to the content, helping search engines understand your page

• They appear in image searches and rich results, bringing extra traffic

• They improve user experience, making people stay longer and bounce less

If your images are too big, generic, badly named, or not described properly, you’re missing easy wins.

2. What image format should you use?

Not all image formats are equal. Some load faster. Some look sharper. Others just eat up space for no good reason.

Here’s a quick breakdown:

• JPEG - Best for most photos. Small file size, decent quality

• PNG - Good for images with transparency or flat colours (like logos). Larger file sizes

• WebP - A modern format created by Google. Great compression and quality. Supported by all modern browsers

General rule: use WebP if you can. If not, go JPEG unless you need transparency.

If you're uploading full-size PNGs straight from Photoshop, stop doing that. Resize and compress first.

3. Should you rename your image files?

Yes. Every time.

A file name like IMG_0298.png tells Google nothing. But oak-dining-table-with-bench.jpg? That’s helpful.

Search engines use file names to understand the image. It’s part of how they match images to search results.

Tips:

• Use hyphens between words (kitchen-units-grey.jpg)

• Keep it simple and relevant

• Add keywords naturally - don’t stuff

Think of file names as basic labels. They help search engines understand the subject matter of the image.

4. What’s the deal with alt text?

Alt text describes the image for screen readers and for Google.

Good alt text = better accessibility and better SEO. It's that simple.

Examples:

• Bad: image1234

• Better: white shaker-style kitchen with chrome handles

Keep it descriptive, short, and relevant. Include keywords if it makes sense - but don’t force them.

And remember: alt text isn’t a caption. It’s a behind-the-scenes tag that gives search engines and users more info about the image.

5. Resize and compress before uploading

Let’s be blunt - big images kill page speed.

You don’t need a 4000-pixel wide photo on your homepage. Resize it. Then compress it.

• Resize to the max width it’ll be displayed at (usually around 1200px for full-width banners)

• Compress to reduce file size. Aim for under 100KB where possible

• Use tools that allow you to control compression levels

Every kilobyte matters when it comes to load speed. And load speed affects SEO.

6. Should you use stock photos or original images?

Search engines prefer original content. That applies to text, video, and yes - images.

Stock photos can work in some places, but:

• They’re often generic and widely used

• They don’t match your actual products or services

• They don’t help search engines understand your specific offer

Wherever possible, use original photos. Especially for product images, case studies, or blog posts about your services.

Unique images are more relevant, more engaging, and more helpful to users and search engines.

7. Add the right attributes and data

It’s not just what the image looks like - it’s what’s under the bonnet.

Here’s what you should check:

• Alt text - write it well

• Title tags - optional, but can add extra info on hover

• Image file names - keep them descriptive

• Structured data - useful for ecommerce and helps search engines understand the image

If you're running an ecommerce site SEO, make sure your product images use markup that helps search engines understand what’s in them.

The more clear signals you send, the better your chances of showing up in search engine results.

8. Use captions - but only when it makes sense

Captions are visible to users and often get more attention than the surrounding text.

Good captions:

• Explain what’s in the image

• Reinforce the content of the article

• Occasionally include a keyword naturally

But don’t force it. If a caption doesn’t add value, leave it out.

Use them where they’re helpful - not as filler.

9. Make sure your images are responsive

Images should look good and load fast on all screen sizes - desktop, tablet, and mobile.

To do that:

• Use srcset to provide multiple image sizes for different screen widths

• Don’t hardcode image widths unless needed

• Test on real devices, not just a browser window shrunk down

Responsive images help users and search engines alike. They’re also part of SEO best practices.

10. Use lazy loading to boost performance

Lazy loading means that images don’t load until the user scrolls down to them.

It:

• Speeds up your initial page load

• Saves data for mobile users

• Improves performance metrics

This is especially important if you have large images below the fold. Lazy loading gives you a fast, lean load time without ditching rich visuals.

11. Include your images in an image sitemap

An image sitemap tells Google where your images live. It helps them get discovered in image search and normal search.

Add the image URLs to your existing XML sitemap, or create a separate one.

Also check that your robots.txt file isn’t blocking important image folders.

Think of a sitemap as a list of all the things you want Google to find. If images matter to your strategy, they should be on the list.

12. Monitor performance and fix weak spots

Optimising images isn’t a one-time job.

Track the results. Adjust. Repeat.

Here’s what to look at:

• Image-related impressions and clicks in your search reports

• Page speed scores

• Bounce rates on image-heavy pages

• Conversion rates tied to product images

If a certain product image drives more traffic or converts better - learn from that. Apply the same approach elsewhere.

Also, look for images that are too large or loading slowly. Fix those.

13. Don’t forget about file type support

Older formats like BMP or TIFF should never go online. They’re massive and often unsupported.

Stick to:

• JPEG

• PNG

• WebP

• SVG (for icons and logos)

Only upload formats that load quickly and work across all devices.

14. Avoid putting key text inside images

Text in images doesn’t help search engines. If you put your product name or CTA inside an image, search engines won’t pick it up.

Use HTML text where possible.

If you must use text in an image (like for a banner), include the same information in surrounding text or in alt attributes.

You want search engines and users to understand the content - even if the image fails to load.

15. Use images to support - not replace - your content

Some people think if they add enough visuals, they can skip the hard work of writing decent content.

That’s not how SEO works.

Use images to:

• Break up long text

• Show products or results visually

• Make the page easier to read

But never rely on images alone to do the job. The content still needs to be solid.

Image SEO: Key Things to Remember

• Use the right image format for the job

• Always rename image files with descriptive names

• Add clear, relevant alt text

• Resize and compress images before uploading

• Use unique images where possible

• Include captions only if they add value

• Make sure your images are responsive

• Add lazy loading for better load speed

• Add images to your sitemap

• Don’t bury key content as text in images

• Use images to support content, not replace it

• Track image performance and improve where needed

Image SEO isn’t technical. It’s about being deliberate. Make your images work for you - not against you.