Images
Images are used on websites to provide more engaging experiences for users, while also presenting more information about a topic. While positive for user experience, images can cause issues for a website’s SEO and performance. Our key takeaways from Google’s ongoing SEO Office Hours sessions cover more insights into the impact of unoptimized images, as well as best practice recommendations from Google.
For more on website content best practices for SEO, read our Guide to Optimizing Website Content for Search — or explore our Website Intelligence Academy resources on SEO & Content.
Linked Image Alt Text Acts as Anchor Text
Add alt text to image links as these act as anchor text, including on mobile pages.
Alt Text is Included as Part of the On-page Text
Alt text is shown when images are turned off in a browser and counts as part of the on-page text.
Google Doesn’t Always Crawl Lazy-loaded Images
Google will not always crawl images which are implemented using lazy loading.
Add Images to Sitemap to Provide Google With More Information
Images can be added for each page of your site within your sitemap along with captions and alt-tags using special sitemap extensions.
Image Links Pass the Same Weight as Text Links
Provided you have alt text on the image, which is equivalent to the anchor text, image links should be treated the same as text links.
Google Doesn’t Detect Text in Images
Google doesn’t do any OCR on images to detect text.
Fetch and Render Will Show Rendered HTML
To help diagnose issues with JavaScript based sites, Google is working on changing Fetch and Render to show the final HTML instead of just showing an image, but John couldn’t give a timeframe for this to be released.
There are no limits to Link Titles, Image Titles and Alt Tags
External Links to Images Don’t Impact Web Search
Linked images from external sites are only factored into image search and don’t affect web search.
Don’t Cloak Lazy Loading Images
If images are not visible to Google because they are lazy loading or below the fold, you shouldn’t be cloaking them for Google.