Image SEO: best image optimization practices

Many website owners focus their SEO efforts on content and keyword optimization, treating images as an afterthought. But images can also rank in image search or alongside text-based search results and bring you valuable traffic if optimized correctly.

Search engines use file names and alt texts to understand the image context. However, image optimization also involves technical factors, like resizing or compression, to ensure a fast page load time and a good user experience.

In this guide, we’ll break down the best image SEO practices for website owners so your images have a chance of appearing in search results.

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What is image SEO?

Image SEO is the practice of optimizing the images on your website so they rank higher in search results, load faster, and are understood by search engines like Google.

It involves optimizing elements like file names and alt texts to help search engines understand what the image shows and its context within the page’s content.

Image SEO also covers technical factors, like file format, compression, and file size, which all contribute to ensuring better loading times.

Why optimize images for SEO?

Optimizing your images for SEO can increase your chances of appearing in image search and improve the experience for site visitors. Here are the main benefits of image SEO:

• Increased visibility in search results. Optimized images have a higher chance of appearing in image search or alongside text-based search results.
• Faster page load times. According to a study by Web Almanac, images take up a large part of total page weight, around 36% on desktop. Choosing the right size and compressing images can help improve Core Web Vitals and page load times.
• Higher chance of appearing in Google Discover. High-quality images that are at least 1,200 pixels can also help you appear in Google Discover and enable large image previews, potentially helping you gain more traffic.
• Higher engagement. Images help improve content readability compared to simple plain text. If they’re optimized for fast speeds, users will stay engaged longer instead of leaving because of a poor experience.
• Topical relevance signaling. Descriptive file names and alt texts help search engines understand your image context and reinforce what your whole page is about.

Where can images appear in Search?

Your site’s images can appear in multiple areas of Google Search, not just the image search. You may also find your image within the Search Engine Results page (SERP), rich snippets, featured snippets, or Google Lens.

• Image Search. Google has a dedicated search tab for images. If your images appear higher in image search results, it can help boost traffic to your site.
• Image results within regular SERP. Google can sometimes show images in regular search results. For example, it can be a row of recipe or product pages together with images.
• Rich results. Websites that add structured data to their code have a higher chance of qualifying for rich results. This means that your search results could include more information about the page than just a title and description. For example, it could display a thumbnail image beside the text-based search result.
• Google Lens. The Google Lens feature lets users search using another image by posting a photo or an image URL. So, your images can be discovered even without a textual query.
• Google Discover. If you use high-quality images, you have a higher chance to appear in the Google Discover feature.
• AI Overviews. Google generates an AI summary for many queries by taking information from multiple sources. Ahrefs found that AI overviews are generated for around 21% of all keywords. Sometimes, it can also pull an image from one of the cited sources to display it on the side of the AI overview.

Best image SEO practices in 2026

Unique images with a well-chosen format and optimized for faster page load times can improve their discoverability. Here are the best image SEO practices that still apply in 2026:

1. Create unique and valuable images

To optimize images for SEO, you first need to create images that provide value to your site visitors or blog readers. Here are different types of images that a website could use:

We don’t recommend using stock images because search engines like Google have already indexed them elsewhere, so they provide little value.

Instead, provide unique photos that signal effort and authenticity, which give you more chances of appearing in image search.

Unique images will also help keep visitors engaged longer, encouraging more purchases or sharing.

2. Use high-quality images

While it’s important that your images are unique, they should also maintain high quality to ensure a good user experience. Images shot in proper lighting and stable focus can help users trust your brand more, making your website or products look professional.

Also, avoid overoptimizing the image. Don’t use different compression tools to reduce the file size of the same image because it will also sacrifice quality.

If you’re editing photos with third-party software, make sure it allows saving in high quality. For example, Canva doesn’t allow changing the quality settings unless you get a paid plan.

3. Check that images are visible and indexable

No matter how much you optimize images, they won’t appear in Google Search if search engines can’t see or index them.

Here are the main things you should check to ensure they’re not blocked:

• Check the robots.txt file. Review that the Google Bot or Googlebot-Image isn’t blocked in your robots.txt file. There shouldn’t be a “Disallow: /” rule under a bot like “User-agent: Googlebot-Image.”
• Don’t use the noindex tag. Avoid using the noindex tag on pages that you want to rank because Google won’t be able to index your images.
• Check images for the HTTP 200 status code. Make sure the images on your pages return an HTTP 200 status code, since broken images may not be indexed.
• Avoid loading images through blocked JavaScript. Images that are embedded directly in the HTML are easier to find and index.

4. Choose the right image format

The right image format depends on where your image is going to appear. Formats like JPEG are usually not suited for logos because they don’t support transparency, while PNGs may not be the best choice for media-heavy pages because the files are larger.

Here are the image formats you should use for your site’s images:

• WebP – best format for website images overall because it’s supported by modern browsers, supports transparency, and offers great compression capabilities. According to Google, it offers 25-34% better compression rates than JPG or PNG at a similar quality.
• SVG – ideal for icons or logos. It scales to any size without sacrificing quality, so it’s usually small in size.
• JPEG – great for photographs and images with complex color grading. It primarily uses lossy compression, meaning it removes unnoticeable details to make file sizes smaller compared to PNG.
• PNG – great for images that require transparency, but it uses lossless compression, so the file size is usually larger than with JPEG.
• GIF – it’s used for animations, but use it sparingly since the file size is large and it can impede your site speed.

5. Create a descriptive image file name

Search engines use image file names to understand what they show. That’s why you should make the file names short but descriptive. Avoid using spaces between words. Instead, separate the words using hyphens.

6. Add alt texts

Image alt texts, or alternative texts, are written descriptions of an image’s content that help search engines like Google understand what’s displayed in it. They’re also used by screen readers to help visually impaired readers understand what the image shows.

Alt texts are stored in a web page’s code as an alt attribute. Here’s an example of what it looks like:

<img src=”pink-running-shoes.jpg” alt=”Pink running shoes placed on a white box”>

Here are the main alt text practices you should follow:

• Write text for functional images. Decorative images don’t need alternative texts. That’s because visually impaired site visitors don’t need the content to be bloated by image descriptions.
• Keep it 125 characters or less. Alt texts should describe the image content without going into too much detail – just mention what matters for context.
• Don’t use vague text. Avoid writing things like “image of” or “screenshot of” and similar details that are irrelevant.

7. Resize images

Images that are too large can impede your Largest Contentful Paint (LCP), or page load time, which Google considers a ranking factor together with other Core Web Vitals metrics.

The right image size depends on the image type and your website builder or theme, but there are still general image size recommendations for websites.

If your image is placed in a container, check its width and don’t use anything larger than the maximum size. For example, if the container is 800x600 pixels, then don’t upload a 3000x2250 pixel image because the browser still has to download the full version before scaling it.

Another tip is to open Google Analytics 4 and check what screen resolutions are most common for your site visitors. You can do that by going to Reports > User > Tech > Overview and finding the Active users by Screen resolution report.

8. Compress images

Image compression is the process of reducing the image file size while maintaining the same dimensions and a similar or nearly identical quality. Compressing images that are too large is important to keep website speed fast.

For example, when we helped optimize the AMARRA clothing website, our automatic image compression tool saved 2.26GB and helped improve the site performance by 34% on desktop.

Here are the types of image compression:

• Lossy compression – type of compression which removes some image data permanently, which results in slight quality reduction but also a smaller file size. In online compressors, you can sometimes choose the quality factor, so pick at least 75 to ensure the quality remains acceptable.
• Lossless compression – type of compression that reduces the file size without removing image data, so the quality remains the same. The file size is reduced, but not as much as with lossy compression.

To compress images, you can use apps or plugins from your website builder’s library. For example, our TinySEO app on Shopify also offers automated image compression. On WordPress, the highest-rated image compression plugin we could find was Smush.

Apps and plugins are useful for bulk image optimization, while for single images, you can use free online compression tools.

9. Use responsive scaling

Responsive scaling is the type of image optimization where the image size is automatically adjusted based on the visitor’s screen size. This means that mobile users don’t need to load the same large file as desktop users, helping improve page load times and the user experience.

Most modern eCommerce platform themes generally use responsive scaling by default, including Shopify, WordPress.com, Wix, and Squarespace.

If you have a custom-made website, then you’ll need to list all available image versions using the srcset and sizes image attributes.

10. Add lazy loading

Browsers try to load every image on a page at once, even when the image is below the fold and isn’t yet needed for the site visitor. Lazy loading is a technique which defers the loading of below-the-fold images, so that the initial page load time becomes faster.

To implement lazy loading, you can add the loading=”lazy” attribute to the <img> tag. It would look something like this:

<img src="photo-file-name.jpg" loading="lazy" alt="Blue leather office chair">

If you want to apply lazy loading store-wide, then you’ll need to add the attribute to different sections in your store. But if you’re not familiar with coding, we highly recommend using an app that automates lazy loading on Shopify, WordPress, or any other website builder that you’re using.

11. Optimize images for AI search

AI models and AI Overviews are also increasingly using images to provide richer answers. Optimizing images for AI follows the same principles as traditional image SEO but it also requires high-quality content and context.

This means that you should always use descriptive file names and alt text and implement structured data so AI models can better understand your page content. Ensure that images are indexable and have clear surrounding context.

All of this potentially increases your chances of appearing in AI Overviews or generated answers in AI models like ChatGPT, Gemini, or Perplexity.

12. Create a sitemap for images

Google recommends creating an image sitemap for better image discoverability. An XML sitemap for images is a file that lists the image URLs on your site that you want search engines to index.

An image sitemap can look something like this:

<?xml version="1.0" encoding="UTF-8"?>

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"

    xmlns:image="http://www.google.com/schemas/sitemap-image/1.1">

  <url>

    <loc>https://example.com/sample1.html</loc>

    <image:image>

      <image:loc>https://example.com/image.jpg</image:loc>

    </image:image>

  </url>

</urlset>

The <image:image> tag includes information about a single image, while <image:loc> is the URL of the image.

13. Use a Content Delivery Network (CDN)

A Content Delivery Network (CDN) helps improve image SEO by optimizing the user experience through faster load times. A CDN is a network of servers that are distributed across different locations and store cached versions of your website.

This means that instead of every site visitor getting your images from a single server, they get them from a server that’s closer to their physical location.

Many of the popular website builders have CDNs enabled by default, including Shopify, WordPress.com, Wix, Squarespace, and BigCommerce.

However, if you’re self-hosting, you can implement a CDN for images by choosing a CDN provider like Cloudflare and integrating it with your site. This includes uploading images, updating the DNS records, and updating the HTML to reference the new image URLs.

14. Enable browser caching

Browser caching allows a site visitor’s browser to store copies of your website files, including images, after the first visit. It helps improve page load times because the browser doesn’t need to re-download the files every time the user revisits the page.

Website builders like Wix, Shopify, and WordPress.com have browser caching enabled by default. If you use another website builder, check their documentation to find out if it’s available.

15. Add structured data

Structured data, also known as schema markup, is a standardized code format that gives search engines and AI models more context about your pages, including their images. It increases your chances of getting rich results, which provide more information about your page in search results, like ratings, images, reviews, or shipping.

You can learn all about structured data on the official schema.org website, but it can take a long time to implement it manually. Google recommends using a plugin or app if you’re already using an eCommerce platform.

Here are some of the apps that offer automatic structured data setup on different platforms:

15. Optimize Open Graph Meta Tags

Open Graph (OG) tags are meta tags that manage how your pages appear when shared on social media platforms, like Facebook or X. It’s not a direct ranking factor, but it helps improve your page representation with the right images, which can potentially influence higher click-through rates.

You can check if OG tags are set on a page using the free TinySEO Chrome extension. Open the extension, click Social, and see if Open Graph data is present.

If it’s not, you can add the OG tags in your page’s <head> section. For example, the og:title determines the title in the preview, og:description shows the short summary, and og:image should be the preview image URL.

Once the OG tags are added, you can check how the shared page would look on social media using the online OpenGraph checker.

How to opt out of inline linking in Google Images?

When your images appear in Google Images, Google serves the full-resolution file directly from your server, which is called inline linking. However, you can opt out of inline linking, so that users who want to download or view the full-resolution version will have to visit your website first.

You can opt out of inline linking by following these steps:

1. Check the HTTP referrer of every incoming image request.
2. If the referrer is Google, return an empty response with a 200 or 204 HTTP status code.

If you’re not familiar with coding, we’d suggest hiring a developer who can do it for you. Always back up your website before making changes to the code.

Final thoughts

Image SEO can help improve search rankings in image search and ensure better page load times. Tasks like file names and alt texts may seem like details, but they help search engines understand what your images actually show and how they relate to the surrounding content.

Start by optimizing the file names and alt texts of all images on your website and implement structured data to get rich results. Then, review which images are too large, resize them, compress the file sizes, and make sure they look responsive on all devices.

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About the author

Kristina Jaruseviciute

Kristina is a Content Lead at TinySEO responsible for informing and educating readers on all things Shopify-related. She covers a broad range of topics around SEO, AI visibility, website performance, and conversion rates to help merchants stand out in a competitive landscape.